cssi/SciSciGPT-SciSciNet huggingface dataset:
Off-the-Grid Line Spectrum Denoising and Estimation With Multiple Measurement Vectors

Compressed Sensing suggests that the required number of samples for reconstructing a signal can be greatly reduced if it is sparse in a known discrete basis, yet many real-world signals are sparse in a continuous dictionary. One example is the spectrally-sparse signal, which is composed of a small number of spectral atoms with arbitrary frequencies on the unit interval. In this paper we study the problem of line spectrum denoising and estimation with an ensemble of spectrally-sparse signals composed of the same set of continuous-valued frequencies from their partial and noisy observations. Two approaches are developed based on atomic norm minimization and structured covariance estimation, both of which can be solved efficiently via semidefinite programming. The first approach aims to estimate and denoise the set of signals from their partial and noisy observations via atomic norm minimization, and recover the frequencies via examining the dual polynomial of the convex program. We characterize the optimality condition of the proposed algorithm and derive the expected error rate for denoising, demonstrating the benefit of including multiple measurement vectors. The second approach aims to recover the population covariance matrix from the partially observed sample covariance matrix by motivating its low-rank Toeplitz structure without recovering the signal ensemble. Performance guarantee is derived with a finite number of measurement vectors. The frequencies can be recovered via conventional spectrum estimation methods such as MUSIC from the estimated covariance matrix. Finally, numerical examples are provided to validate the favorable performance of the proposed algorithms, with comparisons against several existing approaches.
Three-dimensional elastic stress and displacement analysis of finite geometry solids containing cracks

The line method of analysis is applied to the Navier-Cauchy equations of elastic equilibrium to calculate the displacement distributions in various bodies containing cracks. The application of this method to these equations leads to coupled sets of simultaneous ordinary differential equations whose solutions are obtained along sets of lines in a discretized region. When decoupling the equations and their boundary conditions is not possible, the use of a successive approximation procedure permits the analytical solution of the resulting ordinary differential equations. The results obtained show a considerable potential for using this method in the three-dimensional analysis of finite geometry solids and suggest a possible extension of this technique to nonlinear material behavior.
Optimal placement and selection of camera network nodes for target localization

The paper studies the optimal placement of multiple cameras and the selection of the best subset of cameras for single target localization in the framework of sensor networks. The cameras are assumed to be aimed horizontally around a room. To conserve both computation and communication energy, each camera reduces its image to a binary “scan-line” by performing simple background subtraction followed by vertical summing and thresholding, and communicates only the center of the detected foreground object. Assuming noisy camera measurements and an object prior, the minimum mean squared error of the best linear estimate of the object location in 2-D is used as a metric for placement and selection. The placement problem is shown to be equivalent to a classical inverse kinematics robotics problem, which can be solved efficiently using gradient descent techniques. The selection problem on the other hand is a combinatorial optimization problem and finding the optimal solution can be too costly to implement in an energy-constrained wireless camera network. A semi-definite programming approximation for the problem is shown to achieve close to optimal solutions with much lower computational burden. Simulation and experimental results are presented.
Talent, labor quality, and economic development

Abstract We develop a theory of labor quality based on (i) the division of the labor force between unskilled and skilled workers and (ii) investments in skilled workers. In our theory, countries differ in two key dimensions: talent and total factor productivity (TFP). We measure talent using the observed achievement levels from the Programme for International Student Assessment (PISA) scores. Our findings imply that the quality of labor in rich countries is about twice as large as the quality in poor countries. Thus, the implied disparities in TFP levels are smaller relative to the standard growth model using a Mincerian measure of labor quality. In our model, the resulting elasticity of output per worker with respect to TFP is about 2.
Creating a Bootable CD with Custom Boot Options that contains Multiple Distributions

It is often common for people to have more than one operating system (OS) that they use on a regular basis. This can necessitate carrying multiple live or installation CD or DVDs. When multiple OSs are installed on a given machine, boot loaders on the system hard drive allow the users to access the various platforms. However, when the system is located in a public environment such as a computer lab, it is often desirable to hide the existence of any platform other than the default standard platform to avoid confusing the general user. This paper details how to create a CD that contains not only a boot menu to reach all of the OSs installed on your system, but also installation, live and network distributions that can be accessed directly from the single CD media.
Impact of Acknowledgments on Application Performance in 4G LTE Networks

Fourth generation (4G) Long Term Evolution (LTE) is a new mobile phone network standard designed to provide both the capacity and Quality of Service (QoS) needed to support multimedia applications. Recent research in LTE has explored modifications to QoS setups, creating MAC layer schedulers and modifying the current QoS architecture. However, what has not been fully explored are the effects of LTE retransmission choices and capabilities on applications and quality of experience. This work examines the impact of LTE wireless acknowledgment modes and timer settings on Voice over IP (VoIP), file transfer and video streaming applications. Issues explored include interaction between application performance, network transport protocols, LTE acknowledgment mode, and wireless conditions. Network Simulator 3 simulations show that LTE retransmissions improve FTP throughput. With delay sensitive applications, such as VoIP and video, the benefits of LTE retransmissions are dependent on the loss rate and specific LTE settings. LTE providers should configure their networks to use retransmission policies appropriate for the type of application traffic.
Pieces of Pico : Saving Intellectual Freedom in the Public School Library

Since their advent, public school libraries in America have rested upon a delicate balance between subservience to curricular direction and leadership in intellectual development. This historical duality today parallels a curricular-extracurricular distinction recognized in constitutional law – based upon an ambiguous Supreme Court plurality ruling in Board of Education v. Pico (1982) – that has safeguarded the intellectual freedom of youth. However, in a rush to address authoritatively problems such as Internet pornography, school librarians are forgetting their historical dual allegiance. If the line between the curricular and extracurricular is blurred, the former likely will subsume the latter. Not only the intellectual freedom of youth is at risk, but the academic freedom of school librarians themselves, and ultimately, expressive liberty in the society at large, which depends on the education of youth in democratic norms. Bringing together rare historical materials on the establishment of school libraries in America, and the experience of case law concerning expressive freedom in education, this Article counsels against an outcome contrary to the civil rights interests of all concerned.
Cigarette Smoke-related Hydroquinone Dysregulates Mcp-1, Vegf And Pedf Expression In Retinal Pigment Epithelium In Vitro And In Vivo

Background Age-related macular degeneration (AMD) is the leading cause of legal blindness in the elderly population. Debris (termed drusen) below the retinal pigment epithelium (RPE) have been recognized as a risk factor for dry AMD and its progression to wet AMD, which is characterized by choroidal neovascularization (CNV). The underlying mechanism of how drusen might elicit CNV remains undefined. Cigarette smoking, oxidative damage to the RPE and inflammation are postulated to be involved in the pathophysiology of the disease. To better understand the cellular mechanism(s) linking oxidative stress and inflammation to AMD, we examined the expression of pro-inflammatory monocyte chemoattractant protein-1 (MCP-1), pro-angiogenic vascular endothelial growth factor (VEGF) and anti-angiogenic pigment epithelial derived factor (PEDF) in RPE from smoker patients with AMD. We also evaluated the effects of hydroquinone (HQ), a major pro-oxidant in cigarette smoke on MCP-1, VEGF and PEDF expression in cultured ARPE-19 cells and RPE/choroids from C57BL/6 mice.
Data from ISEE-3 for the IMS period

The International Sun-Earth Explorer (ISEE) Project represents a joint effort between the European Space Agency and NASA. The primary objective of the project is the study of the outer magnetosphere. A review is presented concerning the data available from ISEE-3 up to the end of the International Magnetospheric Study (IMS) period (December 31, 1979), taking into account the approaches used to obtain the data. Attention is given to the ISEE-3 as an upstream monitor, ISEE-3 an an observer of the magnetosphere, aspects of ISEE-3 data availability, questions regarding the data link, and the definitive orbit position of ISEE-3 throughout the IMS.
Provably bounded-optimal agents

Since its inception, artificial intelligence has relied upon a theoretical foundation centred around perfect rationality as the desired property of intelligent systems. We argue, as others have done, that this foundation is inadequate because it imposes fundamentally unsatisfiable requirements. As a result, there has arisen a wide gap between theory and practice in AI, hindering progress in the field. We propose instead a property called bounded optimality. Roughly speaking, an agent is bounded-optimal if its program is a solution to the constrained optimization problem presented by its architecture and the task environment. We show how to construct agents with this property for a simple class of machine architectures in a broad class of real-time environments. We illustrate these results using a simple model of an automated mail sorting facility. We also define a weaker property, asymptotic bounded optimality (ABO), that generalizes the notion of optimality in classical complexity theory. We then construct universal ABO programs, i.e., programs that are ABO no matter what real-time constraints are applied. Universal ABO programs can be used as building blocks for more complex systems. We conclude with a discussion of the prospects for bounded optimality as a theoretical basis for AI, and relate it to similar trends in philosophy, economics, and game theory.
Degradation of Methylmercury by Bacteria Isolated from Environmental Samples

Abstract A total of 207 bacterial cultures, isolated from environmental samples, was screened for ability to degrade methylmercury. Of these, 30 were found positive for aerobic demethylation. Twenty-two of these were shown to be facultative anaerobes and 21 of these degraded methylmercury anaerobically. All positive species volatilized methylmercury aerobically, and methane was produced as a degradation product. Although methylmercury degradation was complete in most cases, material balances indicated some of the inorganic mercury formed was not volatilized and is presumed bound to the cells. All positive isolates were tolerant to at least 0.5 μg of methylmercury per ml, and the extent of volatilization of mercury increased with concentration to the threshold value. The results indicate that demethylating species are prevalent in the environment and may be important in suppressing the methylmercury content of sediments.
Comments on quantum Higgs vacua

We study two-dimensional $$ \mathcal{N}=\left(4,4\right) $$ supersymmetric gauge theories which do not have classical Higgs branches, but are believed to have isolated quantum Higgs vacua. We provide arguments for the existence of such vacua based on brane dynamics in string theory and the supersymmetric partition sums of the gauge theories.
CONTINUOUS METABOLIC AND CARDIOVASCULAR MEASUREMENTS ON A MONKEY SUBJECT DURING A SIMULATED 6-DAY SPACELAB MISSION

A 10-kg male pig-tailed monkey (Macaca nemestrina) was selected as an optimal species for spaceflight studies on weightlessness. Three days before the simulated launch, the animal was placed in a fiberglass pod system to provide continuous measurement of respiratory gas exchange. Attention is given to examining the effects of weightlessness on several basic parameters of metabolic and cardiovascular function in an adult nonhuman primate. The 10.7-day total simulated-experiment period consisted of preflight 2.6 days, inflight 6.3 days, and postflight 1.8 days. Statistically significant diurnal variation was noted in oxygen consumption and CO2 production rates, body temperature and HR, but not in respiratory quotient or blood pressure. The high quality of the continuous data obtained demonstrates the feasibility of performing sound physiological experimentation on nonhuman primates in the Spacelab environment.
PeerNet: Pushing Peer-to-Peer Down the Stack

An unwritten principle of the Internet Protocol is that the IP address of a node also serves as its identifier. We observe that many scalability problems result from this principle, especially when we consider mobile networks. In this work, we examine how we would design a network with a separation between address and identity. We develop PeerNet, a peer-to-peer-based network layer for large networks. PeerNet is not an overlay on top of IP, it is an alternative to the IP layer. In PeerNet, the address reflects the node’s current location in the network. This simplifies routing significantly but creates two new challenges: the need for consistent address allocation and an efficient node lookup service. We develop fully distributed solutions to address these and other issues using a per-node state of O(log N), where N is the number of nodes in the network. PeerNet is a radically different alternative to current network layers, and our initial design suggests that the PeerNet approach is promising and worth further examination.
Diverse Inflammatory Cytokines Induce Selectin Ligand Expression on Murine CD4 T Cells via p38α MAPK

Selectins are glycan-binding adhesion molecules that mediate the initial steps of leukocyte recognition of endothelium. Cytokines control numerous aspects of CD4 Th cell differentiation, but how cytokines control the induction of ligands for E- and P-selectin on Th cell subsets remains poorly understood. Among 20 cytokines that affect Th cell differentiation, we identified six that induce expression of selectin ligands on murine CD4 T cells above the low levels associated with TCR engagement: IL-12, IL-18, IL-27, IL-9, IL-25, and TGF-β1. Collectively, these six cytokines could potentially account for selectin ligand expression on all of the currently defined nonsessile Th cell lineages, including Th1, Th2, Th9, and Th17 cells, as well as regulatory T cells. Induction of selectin ligand expression by each of these six cytokines was almost completely inhibited by pharmacologic inhibition of p38 MAPK, but not other MAPKs, or by conditional genetic deletion of p38α MAPK. Analysis of the expression of key glycosyltransferase genes revealed that p38α signaling was selectively required for induction of Fut7 and Gcnt1 but not for the induction of St3gal4 or St3gal6. Constitutively active MKK6, an immediate upstream activator of p38 MAPK, induced selectin ligand expression equivalent to that of cytokines, and this induction was completely dependent on the expression of p38α. Our results identify the repertoire of cytokines responsible for selectin ligand induction on CD4 T cells and provide a mechanistic link between Th cell development and T cell migration.
What Makes a Leader

Superb leaders have very different ways of directing a team, a division, or a company. Some are subdued and analytical; others are charismatic and go with their gut. And different situations call for different types of leadership. Most mergers need a sensitive negotiator at the helm, whereas many turnarounds require a more forceful kind of authority. Psychologist and noted author Daniel Goleman has found, however, that effective leaders are alike in one crucial way: they all have a high degree of what has come to be known as emotional intelligence. In fact, Goleman's research at nearly 200 large, global companies revealed that emotional intelligence--especially at the highest levels of a company--is the sine qua non for leadership. Without it, a person can have first-class training, an incisive mind, and an endless supply of good ideas, but he still won't make a great leader. The components of emotional intelligence--self-awareness, self-regulation, motivation, empathy, and social skill--can sound unbusinesslike. But exhibiting emotional intelligence at the workplace does not mean simply controlling your anger or getting along with people. Rather, it means understanding your own and other people's emotional makeup well enough to move people in the direction of accomplishing your company's goals. In this article, the author discusses each component of emotional intelligence and shows through examples how to recognize it in potential leaders, how and why it leads to measurable business results, and how it can be learned. It takes time and, most of all, commitment. But the benefits that come from having a well-developed emotional intelligence, both for the individual and the organization, make it worth the effort.
Estimation of a Two-component Mixture Model with Applications to Multiple Testing

We consider a two-component mixture model with one known component. We develop methods for estimating the mixing proportion and the other unknown distribution nonparametrically, given i.i.d. data from the mixture model. We use ideas from shape restricted function estimation and develop “tuning parameter free” estimators that are easily implementable and have good finite sample performance. We establish the consistency of our procedures. Distribution-free finite sample lower confidence bounds are developed for the mixing proportion. The identifiability of the model, and the estimation of the density of the unknown mixing distribution are also addressed. We discuss the connection with the problem of multiple testing and compare our procedure with some of the existing methods in that area through simulation studies. We also analyse two data sets, one arising from an application in astronomy and the other from a microarray experiment.
Decompositions of small tensor powers and Larsen’s conjecture

We classify all pairs (G,V) with G a closed subgroup in a classical group with natural module V over the complex numbers such that G has the same composition factors on the kth tensor power of V, for a fixed (small) k. In particular, we prove Larsen's conjecture stating that for dim(V) > 6 and k = 4, there are no such G aside from those containing the derived subgroup of the classical group. We also find all the examples where this fails for dim(V) < 7. As a consequence of our results, we obtain a short proof of a related conjecture of Katz. These conjectures are used in Katz's recent works on monodromy groups attached to Lefschetz pencils and to character sums over finite fields. Modular versions of these conjectures are also studied, with a particular application to random generation in finite groups of Lie type.
Window-based greedy contention management for transactional memory

We consider greedy contention managers for transactional memory for M × N execution windows of transactions with M threads and N transactions per thread. Assuming that each transaction has duration τ and conflicts with at most C other transactions inside the window, a trivial greedy contention manager can schedule them within τCN time. In this paper, we explore the theoretical performance boundaries of this approach from the worst-case perspective. Particularly, we present and analyze two new randomized greedy contention management algorithms. The first algorithm Offline-Greedy produces a schedule of length O(τ ċ (C + N log(MN))) with high probability, and gives competitive ratio O(log(MN)) for C ≤ N log(MN). The offline algorithm depends on knowing the conflict graph which evolves while the execution of the transactions progresses. The second algorithm Online-Greedy produces a schedule of length O(τ ċ (C log(MN) + N log2(MN))), with high probability, which is only a O(log(NM)) factor worse, but does not require knowledge of the conflict graph. Both of the algorithms exhibit competitive ratio very close to O(s), where s is the number of shared resources. Our algorithms provide new tradeoffs for greedy transaction scheduling that parameterize window sizes and transaction conflicts within the window.
A new look at wireless scheduling with delayed information

The performance of wireless scheduling algorithms directly depends on the availability and accuracy of channel state information (CSI) at the scheduler. As CSI updates must propagate across the network, they are delayed as they arrive at the controller. In this paper, we analyze the effect that delayed CSI has on the throughput performance of scheduling in wireless networks. By accounting for the delays in CSI as they relate to the network topology, we revisit the comparison between centralized and distributed scheduling, which is analyzed as a trade-off between using delayed CSI and making imperfect scheduling decisions. In particular, we prove that there exist conditions under which distributed scheduling outperforms the optimal centralized scheduling policy. We characterize the point at which distributed scheduling outperforms centralized scheduling for tree networks, illustrating the impact of topology on throughput.
Conformational Changes in Two Inter-Helical Loops of Mhp1 Membrane Transporter.

Mhp1 is a bacterial secondary transporter with high-resolution crystal structures available for both the outward- and inward-facing conformations. Through molecular dynamics simulations of the ligand-free Mhp1 as well as analysis of its crystal structures, here we show that two inter-helical loops, respectively located at the extra- and intracellular ends of the “hash motif” in the protein, play important roles in the conformational transition. In the outward- and inward-facing states of the protein, the loops adopt different secondary structures, either wrapped to the end of an alpha-helix, or unwrapped to extended conformations. In equilibrium simulations of 100 ns with Mhp1 in explicit lipids and water, the loop conformations remain largely stable. In targeted molecular dynamics simulations with the protein structure driven from one state to the other, the loops exhibit resistance and only undergo abrupt changes when other parts of the protein already approach the target conformation. Free energy calculations on the isolated loops further confirm that the wrapping/unwrapping transitions are associated with substantial energetic barriers, and consist of multiple sequential steps involving the rotation of certain backbone torsion angles. Furthermore, in simulations with the loops driven from one state to the other, a large part of the protein follows the loops to the target conformation. Taken together, our simulations suggest that changes of the loop secondary structures would be among the slow degrees of freedom in the conformational transition of the entire protein. Incorporation of detailed loop structures into the reaction coordinate, therefore, should improve the convergence and relevance of the resulting conformational free energy.
Efficient execution of parallel applications in multiprogrammed multiprocessor systems

Existing techniques for sharing the processing resources in multiprogrammed shared-memory multiprocessors, such as time-sharing, space-sharing and gang-scheduling, typically sacrifice the performance of individual parallel applications to improve overall system utilization. We present a new processor allocation technique that dynamically adjusts the number of processors an application is allowed to use for the execution of each parallel section of code based on the current system load. This approach exploits the maximum parallelism possible for each application without overloading the system. We implement our scheme on a Silicon Graphics Challenge multiprocessor system and evaluate its performance using applications from the Perfect Club benchmark suite and synthetic benchmarks. Our approach shows significant improvements over traditional time-sharing and gang-scheduling. It has a performance comparable to, or slightly better than, static space-sharing, but our strategy is more robust since, unlike static space-sharing, it does not require a priori knowledge of the applications' parallelism characteristics.
(If) size matters: size-hiding private set intersection

Modern society is increasingly dependent on, and fearful of, the availability of electronic information. There are numerous examples of situations where sensitive data must be - sometimes reluctantly - shared between two or more entities without mutual trust. As often happens, the research community has foreseen the need for mechanisms to enable limited (privacy-preserving) sharing of sensitive information and a number of effective solutions have been proposed. Among them, Private Set Intersection (PSI) techniques are particularly appealing for scenarios where two parties wish to compute an intersection of their respective sets of items without revealing to each other any other information. Thus far, "any other information" has been interpreted to mean any information about items not in the intersection. In this paper, we motivate the need for Private Set Intersection with a stronger privacy property of hiding the size of the set held by one of the two entities ("client"). We introduce the notion of Size-Hiding Private Set Intersection (SHI-PSI) and propose an efficient construction secure under the RSA assumption in the Random Oracle Model. We also show that input size-hiding is attainable at very low additional cost.
Radio Emission from Quiescent Filaments

Full-disk VLA synthesis maps of the quiet Sun indicate that filaments can be seen in emission at 91.6-cm wavelength; they are detected in absorption at shorter microwave wavelengths. The 91.6-cm emission has a brightness temperature of TB = 3 x 105 K. It is hotter, wider and longer than the underlying filament detected at Hα wavelengths, but the similarity between the shape, position, elongation and orientation of the radio and optical features suggests their close association. The 91.6-cm emission is attributed to the thermal bremsstrahlung of a hot transition sheath that envelopes the Ha filament and acts as an interface between the cool, dense Hα filament and the hotter, rarefied corona. The transition sheath is seen in emission because of the lower optical depth of the corona at 90-cm wavelength, and the width of this sheet is 109 cm. A power law gradient in pressure provides a better match to the observations than a constant pressure model; definitive tests of theoretical models await simultaneous multi-wavelength studies of filaments at different observing angles. When the thermal bremsstrahlung is optically thin, the magnetic field strength in the transition sheath can be inferred from the observed circular polarization. Variable physical parameters of the sheath, such as width, electron density, and electron temperature, can explain controversial reports of the detection of, or the failure to detect, the meterwavelength counterpart of Hα filaments.
Theory of Reflectance and Emittance Spectroscopy

Acknowledgements 1. Introduction 2. Electromagnetic wave propagation 3. The absorption of light 4. Specular reflection 5. Single particle scattering: perfect spheres 6. Single particle scattering: irregular particles 7. Propagation in a nonuniform medium: the equation of radiative transfer 8. The bidirectional reflectance of a semi-infinite medium 9. The opposition effect 10. A miscellany of bidirectional reflectances and related quantities 11. Integrated reflectances and planetary photometry 12. Photometric effects of large scale roughness 13. Polarization 14. Reflectance spectroscopy 15. Thermal emission and emittance spectroscopy 16. Simultaneous transport of energy by radiation and conduction Appendix A. A brief review of vector calculus Appendix B. Functions of a complex variable Appendix C. The wave equation in spherical coordinates Appendix D. Fraunhoffer diffraction by a circular hole Appendix E. Table of symbols Bibliography Index.
Helical screw expander evaluation project

A one MW helical rotary screw expander power system for electric power generation from geothermal brine was evaluated. The technology explored in the testing is simple, potentially very efficient, and ideally suited to wellhead installations in moderate to high enthalpy, liquid dominated field. A functional one MW geothermal electric power plant that featured a helical screw expander was produced and then tested with a demonstrated average performance of approximately 45% machine efficiency over a wide range of test conditions in noncondensing, operation on two-phase geothermal fluids. The Project also produced a computer equipped data system, an instrumentation and control van, and a 1000 kW variable load bank, all integrated into a test array designed for operation at a variety of remote test sites. Data are presented for the Utah testing and for the noncondensing phases of the testing in Mexico. Test time logged was 437 hours during the Utah tests and 1101 hours during the Mexico tests.
On preconditioners for the Laplace double‐layer in 2D

The discretization of the double-layer potential integral equation for the interior Dirichlet Laplace problem in a domain with smooth boundary results in a linear system that has a bounded condition number. Thus, the number of iterations required for the convergence of a Krylov method is, asymptotically, independent of the discretization size $N$. Using the Fast Multipole Method (FMM) to accelerate the matrix-vector products, we obtain an optimal $\mathcal{O}(N)$ solver. In practice, however, when the geometry is complicated, the number of Krylov iterations can be quite large---to the extend that necessitates the use of preconditioning. We summarize the different methodologies that have appeared in the literature (single-grid, multigrid, approximate sparse inverses) and we propose a new class of preconditioners based on an FMM-based spatial decomposition of the double-layer operator. We present an experimental study in which we compare the different approaches and we discuss the merits and shortcomings of our approach. Our method can be easily extended to other second-kind integral equations with non-oscillatory kernels in two and three dimensions.
Models for automated tube performance calculations

High power RF systems, as typically used in fusion research devices, utilize vacuum tubes. Evaluation of vacuum tube performance involves data taken from tube operating curves. The acquisition of data from such graphical sources is a tedious process. A simple modeling method is presented that will provide values of tube currents for a given set of element voltages. These models may be used as subroutines in iterative solutions of amplifier operating conditions for a specific loading impedance.
Automatic extraction of deceptive behavioral cues from video

This research initiative is an initial investigation into a novel approach for deriving indicators of deception from video-taped interaction. The team utilized two-dimensional spatial inputs extracted from video to construct a set of discrete and inter-relational features. The features for thirty-eight video interactions were then analyzed using discriminant analysis. Additionally, features were used to build a multivariate regression model. Through this exploratory study, the team established the validity of the approach, and identified a number of promising features, opening the door for further investigation.
Efficient computationally private information retrieval from anonymity or trapdoor groups

A Private Information Retrieval (PIR) protocol allows a user to obtain information from a database in a manner that prevents the database from knowing which data was retrieved. Although substantial progress has been made in the discovery of computationally PIR (cPIR) protocols with reduced communication complexity, there has been relatively little work in reducing the computational complexity of cPIR protocols. In particular, Sion and Carbunar argue that existing cPIR protocols are slower than the trivial PIR protocol (in overall performance). In this paper, we present a new family of cPIR protocols with a variety of security and performance properties. Our protocols enable much lower CPU overhead for the database server. When the database is viewed as a bit sequence, only addition operations are performed by the database server. The security of the general version of our protocol depends on either a Hidden Modular Group Order (HMGO) assumption, (a new assumption), or sender anonymity, and we present two specialized protocols, each of which depends on one of the two assumptions, respectively. For our trapdoor group protocol, we assume (the HMGO assumption) that given only the elements be1, ..., bet in the group Zm, where ei < m/t and t is small, it is hard to compute the group order m. One version of our cPIR protocol depends only on sender anonymity, which to our knowledge, is the first cPIR protocol to depend only on an anonymity assumption. Our prototype implementation shows that our performance compares favorably with existing cPIR protocols.
Learning natural selection from the site frequency spectrum

Genetic adaptation to external stimuli occurs through the combined action of mutation and selection. A central problem in genetics is to identify loci responsive to specific selective pressures. Over the last two decades, many tests have been proposed to identify genomic signatures of natural selection. However, the power of these tests changes unpredictably from one dataset to another, with no single dominant method. We build upon recent work that connects many of these tests in a common framework, by describing how positive selection strongly impacts the observed site frequency spectrum (SFS). Many of the proposed tests quantify the skew in SFS to predict selection. Here, we show that the skew depends on many parameters, including the selection coefficient, and time since selection. Moreover, for each of the different regimes of positive selection, informative features of the scaled SFS can be learned from simulated data and applied to population-scale variation data. Using support vector machines, we develop a test that is effective over all selection regimes. On simulated datasets, our test outperforms existing ones over the entire parameter space. We apply our test to variation data from Drosophila melanogaster populations adapted to hypoxia, and identify new loci that were missed by previous approaches, but strengthen the role of the Notch pathway in hypoxia tolerance.
Analyzing Urban Systems : Have Megacities Become Too Large?

The trend toward ever greater urbanization continues unabated across the globe. According to the United Nations, by 2025 closes to 5 billion people will live in urban areas. Many cities, especially in the developing world, are set to explode in size. Over the next decade and a half, Lagos is expected to increase its population 50 percent, to nearly 16 million. Naturally, there is an active debate on whether restricting the growth of megacities is desirable and whether doing so can make residents of those cities and their countries better off. When analyzing whether megacities have become too large, policy makers often analyze a single city in depth. But no city is an island: improving urban infrastructure in one city might attract migrants, and a negative shock in one location can be mitigated because people can move to another. Considering the general equilibrium effects of any such urban policy is thus key. That is, when deciding whether to make medium-size cities more attractive, policy makers need to understand how cities of all sizes will be affected. The next section briefly summarizes the theoretical framework and discusses which data are needed. The third section implements the methodology for the benchmark case of the United States. The fourth section does the same for China and Mexico and compares the findings. And the last section concludes. A technical online appendix guides the reader through a practical, step-by-step, discussion of how to do the analysis.
A note on large gauge transformations in double field theory

We give a detailed proof of the conjecture by Hohm and Zwiebach in double �eld theory. This result implies that their proposal for large gauge transformations in terms of the Jacobian matrix for coordinate transformations is, as required, equivalent to the standard exponential map associated with the generalized Lie derivative along a suitable parameter.
Do industries lead stock markets? A reexamination

Hong et al. (2007) report that a number of U.S. industry returns can forecast the stock market using monthly data. Reexamining their results with an extended period, 1946–2013, and data, 48 industries, I find that only one to seven industries have significant predictive ability for the stock market, depending on the significance level (10% or 5%) and the model specifications used. However, I find some evidence of the opposite predictive direction from the stock market to industries. The stock market also performs better than industries in predicting economic growth. Using similar data, 34 industries, and period, 1946–2002, as Hong et al., I find that the results are less significant after data revisions. My overall results are consistent with the efficient market hypothesis.
Work Environment and OPT-out Rates at Motherhood across High-Education Career Paths

Observing a sample of Harvard alumnae in their late thirties, the authors study the relationship between workplace flexibility and the labor force participation of mothers. They first document a large variation in labor force participation rates across higher education fields. Mindful of the possibility of systematic patterns in the types of women who complete various graduate degrees, they use the rich information available for the sample, supplemented by the longitudinal nature of a subset of these data, to assess the extent to which these labor supply patterns may reflect variation in the difficulty of combining work with family. Although ruling out systematic sorting entirely is not possible, their evidence suggests that inflexible work environments “push” women out of the labor force at motherhood.
Reducing Packaging Waste and Cost via Consumer Price Discounts

Low-waste packaging may imply an inconvenience to consumers and cause firms to offer a compensating price discount. For example, Starbucks’ “Take the Mug Pledge” campaign provides a 10-cent discount for customers who purchase coffee without a standard cup (i.e., customers provide their own cup). Understanding how such a discount drives demand and profit is the focus of this paper. We consider a monopolist that can offer a reduced-packaging option for its product at a variable cost savings. That option implies a transactional “inconvenience” cost for consumers. While that transactional cost is generally positive, our model also permits some consumers to associate convenience with reduced packaging. We derive the optimal price and discount that maximize profits. We show the optimal discount is bounded by the magnitude of the variable cost savings associated with the packaging reduction. We explore when the optimal discount is negative (a price premium), which requires a specific proportion of consumers to associate convenience with reduced packaging. We also derive conditions under which the firm should price to eliminate demand for the standard product, rather than segment the market, to leverage the variable cost savings of reduced packaging. When the variable cost savings are low (e.g., as is true for Starbucks), we show the profit curve for the segmenting policy is relatively flat for a discount up to several multiples of the cost differential. Finally, we demonstrate the potential for the reduced packaging option, with optimal discounting, to simultaneously increase profit and consumer surplus while reducing waste. Submitted: September 8, 2011. Revised: February 2, 2012; April 30, 2012. Accepted: May 30, 2012. Subject Areas: Operations/Marketing interface, pricing, packaging, source reduction.
Expectation propagation for approximate Bayesian inference

This paper presents a new deterministic approximation technique in Bayesian networks. This method, "Expectation Propagation," unifies two previous techniques: assumed-density filtering, an extension of the Kalman filter, and loopy belief propagation, an extension of belief propagation in Bayesian networks. Loopy belief propagation, because it propagates exact belief states, is useful for a limited class of belief networks, such as those which are purely discrete. Expectation Propagation approximates the belief states by only retaining expectations, such as mean and varitmce, and iterates until these expectations are consistent throughout the network. This makes it applicable to hybrid networks with discrete and continuous nodes. Experiments with Gaussian mixture models show Expectation Propagation to be donvincingly better than methods with similar computational cost: Laplace's method, variational Bayes, and Monte Carlo. Expectation Propagation also provides an efficient algorithm for training Bayes point machine classifiers.
Subjective Beliefs and ex ante Trade

We study a definition of subjective beliefs applicable to preferences that allow for the perception of ambiguity, and provide a characterization of such beliefs in terms of market behavior. Using this definition, we derive necessary and sufficient conditions for the efficiency of ex ante trade and show that these conditions follow from the fundamental welfare theorems. When aggregate uncertainty is absent, our results show that full insurance is efficient if and only if agents share some common subjective beliefs. Our results hold for a general class of convex preferences, which contains many functional forms used in applications involving ambiguity and ambiguity aversion. We show how our results can be articulated in the language of these functional forms, confirming results existing in the literature, generating new results, and providing a useful tool for applications.
Entanglement entropy of Wilson surfaces from bubbling geometries in M-theory

We consider solutions of eleven-dimensional supergravity constructed in [1, 2] that are half-BPS, locally asymptotic to AdS7 S 4 and are the holographic dual of heavy Wilson surfaces in the six-dimensional (2; 0) theory. Using these bubbling solutions we calculate the holographic entanglement entropy for a spherical entangling surface in the presence of a planar Wilson surface. In addition, we calculate the holographic stress tensor and, by evaluating the on-shell supergravity action, the expectation value of the Wilson surface operator.
Characterization of Morphology and Mechanical Properties of Glass Interior Irradiated by Femtosecond Laser

Femtosecond laser pulses were focused in the interior of a single fused silica piece. Proper use of optical and laser processing parameters generated structural rearrangement of the material through a thermal accumulation mechanism, which could be potentially used for the transmission welding process. The morphology of generated features was studied using differential interference contrast optical microscopy. In addition, the predictive capability of the morphology is developed via a finite element analysis. The change in mechanical properties was studied through employment of spatially resolved nanoindentation. The specimen was sectioned and nanoindents were applied at the cross section to examine mechanical responses of the laser-modified region. Fracture toughness measurements are carried out to investigate the effects of the laser treatment on strength of the glass.
Optimal Search with Learning

Abstract The sequential search problem, without the assumption that the searcher knows the underlying distribution, is investigated. Both search with recall and without recall are examined. Sufficient conditions for the existence of optimal stopping rules with the reservation property are provided. Comparative static results with respect to stochastic dominance (appropriately defined) are obtained.
Linear groups of finite cohomological dimension

Our main result provides necessary and sufficient conditions for a finitelygenerated subgroup of GLn(C), n > 0, to have finite virtual cohomological dimension. A group has finite virtual cohomological dimension (VCD) if it has a subgroup of finite index which has finite cohomological dimension; this dimension is, in fact, the same for all torsion-free subgroups of finite index. It is, of course, necessary for a group r with VCD(T) Q), is independent of the choice of solvable series; thus, for a polycyclic group r, h(T) is the number of infinite factors in a normal series with cyclic quotients. We announce our main result.
Synthesis of Metal-Chelating Polymerizable Phospholipids

Abstract Two routes for the synthesis of metal chelating phospholipids are reported. An iminodiacetic acid functionality served as metal chelating site in the polar headgroup region of a phospholipid while a tricosa-10,12-diynoyl group linked to the glycerol backbone, made up the polymerizable hydrocarbon region.
Magneto-optical studies of compound semiconductors

Abstract A simultaneous determination of both the conduction and valence-band dispersion curves (and masses) from a single compound semiconductor quantum-well structure using magnetoluminescence is discussed. Data from InGaAs/GaAs strained-single-quantum wells and GaAs/AlGaAs lattice matched quantum wells are presented. The conduction bands are found to be parabolic for densities approaching 1 × 1012cm−2. However, the valence bands are highly nonparabolic and strongly affected by heavy-hole light-hole mixing.
Conversational action patterns in dialogs

Systems that interact in dialogs need to understand linguistic actions being used by one another and know which linguistic actions are appropriate for their own uses. We introduce a model based on conversational action patterns to describe and predict speech acts in natural language dialogs and to specify appropriate actions to satisfy the system's goals. A modified production system was used to implement the formalism. The salient characteristics of the production system are:(1) Affects (emotions) can modify the interpretation of external events and alter the flow of control of the systems.(2) The system uses overlapping and parallel rules to predict and generate overlapping linguistic events in dialog situations.