cssi/SciSciGPT-SciSciNet huggingface dataset:
Are foreign investors attracted to weak environmental regulations? Evaluating the evidence from China

One of the most contentious debates today is whether pollution-intensive industries from rich countries relocate to poor countries with weaker environmental standards, turning them into pollution havens. Empirical studies to date show little evidence to support the pollution haven hypothesis, but suffer potentially from omitted variable bias, specification, and measurement errors. The authors estimate the strength of pollution-haven behavior by examining the location choices of equity joint venture (EJV) projects in China. They derive a location choice model from a theoretical framework that incorporates the firm's production and abatement decision, agglomeration, and factor abundance. The authors estimate conditional logit and nested logit models using new data sets containing information on a sample of EJV projects, effective environmental levies on water pollution, and estimates of Chinese pollution-intensity for 3-digit ISIC (International Standard Industrial Classification) industries. Results from 2,886 manufacturing joint venture projects from 1993-96 show that EJVs from all source countries go into provinces with high concentrations of foreign investment, relatively abundant stocks of skilled workers, concentrations of potential local suppliers, special incentives, and less state ownership. Environmental stringency does affect location choice, but not as expected. Low environmental levies are a significant attraction only for joint ventures in highly-polluting industries with partners from Hong Kong, Macao, and Taiwan (China). In contrast, joint ventures with partners from OECD sources are not attracted by low environmental levies, regardless of the pollution intensity of the industry. The authors discuss the likely role of technological differences in explaining these results.
Predictors of change in grip strength over 3 years in the African American health project.

Objectives: To examine factors associated with change in grip strength. Method: Grip strength was measured at baseline and 3 years later. Change was divided into “decreased ≥5 kg,” “increased ≥5 kg,” and “no change” and analyzed using multinomial multivariable logistic regression. Results: Decline in grip strength was more likely for men, those reporting having cardiovascular disease, and those with instrumental activities of daily living, lower body functional limitations, high diastolic blood pressure, higher physical activity, and greater body mass. Decline was less likely among those ever having Medicaid, those with basic activities of daily living disabilities, and those unable to see a doctor in past year due to cost. Gain in grip strength was more likely for men and those with instrumental activities of daily living disabilities, lower body functional limitations, high diastolic blood pressure, and higher physical activity; it was less likely for older participants. Discussion: Results can be used ...
Gold‐Catalyzed Hydroamination of Alkynes and Allenes with Parent Hydrazine

An Au—hydrazine complex, generated in situ, efficiently catalyzes the hydroamination of alkynes with hydrazine.
Embedded Reference Electrode for Potential-Monitoring of Cathodic Protective Systems

Ag/AgCl reference electrodes were prepared in 0.03 M FeCl 3 solution using micrometer-scale silver (Ag) wires and embedded between the topcoat and metal-rich primer of a sacrificial coating system. The arrangement allows in situ measurement of the open-circuit potential (OCP), an indicator of the level of protection afforded by the coating to the substrate, via the embedded reference electrode (ERE) and aims to eliminate the standard, less-accurate practice of scheduled maintenance. This methodology allows the possibility of upgrading the monitoring and control systems presently used for impressed cathodic protection in addition to permitting the in situ observation of the corrosion protection levels for metal-rich sacrificial coatings. Measurements of the metal-rich primer/substrate OCP vs the ERE and vs a saturated calomel electrode (SCE) as a function of exposure time were the key experimental techniques to validate the use of an embedded electrode. Potentiodynamic experiments were executed to polarize the system using an SCE and second potentiostat. The impressed potentials were successfully monitored concurrently via the ERE and original potentiostat. Strengthened by the in situ OCP measurements with B 117 salt spray chamber, this study shows the feasibility of the Ag/AgCl ERE for use in cathodic protective systems by effectively relaying OCP information.
WEAKLY GROUP-THEORETICAL AND SOLVABLE FUSION CATEGORIES

We introduce two new classes of fusion categories which are obtained by a certain procedure from finite groups – weakly group-theoretical categories and solvable categories. These are fusion categories that are Morita equivalent to iterated extensions (in the world of fusion categories) of arbitrary, respectively solvable finite groups. Weakly group-theoretical categories have integer dimension, and all known fusion categories of integer dimension are weakly group-theoretical. Our main results are that a weakly group-theoretical category C has the strong Frobenius property (i.e., the dimension of any simple object in an indecomposable C-module category divides the dimension of C), and that any fusion category whose dimension has at most two prime divisors is solvable (a categorical analog of Burnside's theorem for finite groups). This has powerful applications to classification of fusion categories and semsisimple Hopf algebras of a given dimension. In particular, we show that any fusion category of integer dimension <84 is weakly group-theoretical (i.e. comes from finite group theory), and give a full classification of semisimple Hopf algebras of dimensions pqr and pq2, where p,q,r are distinct primes.
High-frequency acceleration feedback in wave variable telerobotics

The human hand is very sensitive to the high-frequency accelerations produced by tool contact with a hard object, yet most time delayed telerobots neglect this feedback band entirely in order to achieve stability. We present a control architecture that both incorporates this important information and provides the ability to scale and shape it independently of the low-frequency force feedback. Leveraging the clean power flows afforded by wave variables, this augmented controller preserves the passivity of any environment that it renders to the user, but is not subject to the limitations of being passive itself. This architecture guarantees stability in the presence of communication delay while achieving a level of feedback not possible with a passive controller. We show experimentally that this feedback augmentation and shaping can present a high-frequency acceleration profile to the user's hand that is similar to that experienced by the slave end effector. Two simple user studies also show that the feedback augmentation improves the user's perception, performance, and confidence with the given tasks. We anticipate that these natural haptic cues will make teleoperative systems easier to use and thus more widely applicable.
Nonlinear growth of strongly unstable tearing modes

Rutherford`s theory of the tearing instability is extended to cases where current nonlinearities are important, such as long wavelength modes in current slabs and the m = 1 instability in tokamaks with moderately large aspect-ratios. Of particular interest is the possibility that the associated magnetic islands, as a result of secondary instabilities, have a singular response to the Ohmic diffusion of the current. A family of islands is used to test this possibility; it is found that the response remains bounded.
Online Learning: Random Averages, Combinatorial Parameters, and Learnability

We develop a theory of online learning by defining several complexity measures. Among them are analogues of Rademacher complexity, covering numbers and fat-shattering dimension from statistical learning theory. Relationship among these complexity measures, their connection to online learning, and tools for bounding them are provided. We apply these results to various learning problems. We provide a complete characterization of online learnability in the supervised setting.
Enediynes, enyne-allenes, their reactions, and beyond

Enediynes undergo a Bergman cyclization reaction to form the labile 1,4-didehy-drobenzene (p-benzyne) biradical. The energetics of this reaction and the related Schreiner–Pascal reaction as well as that of the Myers–Saito and Schmittel reactions of enyne-allenes are discussed on the basis of a variety of quantum chemical and available experimental results. The computational investigation of enediynes has been beneficial for both experimentalists and theoreticians because it has led to new synthetic challenges and new computational methodologies. The accurate description of biradicals has been one of the results of this mutual fertilization. Other results have been the computer-assisted drug design of new antitumor antibiotics based on the biological activity of natural enediynes, the investigation of hetero- and metallo-enediynes, the use of enediynes in chemical synthesis and materials science, or an understanding of catalyzed enediyne reactions. For further resources related to this article, please visit the WIREs website.
Optimal projection for multidimensional signal detection

The concept of projection, in which a set of samples is represented by a single sample, can be used to reduce the dimensionality of the data, thereby simplifying the detection process. A projection method that maximizes the probability of signal detection for a fixed probability of false alarm is derived. Samples containing signal plus noise and noise alone are assumed to be independently and identically distributed, but are otherwise arbitrary. Only one sample in the set of samples projected onto a single sample may contain the signal. It is shown that for high signal-to-noise ratios, the optimal projection algorithm can be approximated as the maximum-value projection scheme, and for low signal-to-noise ratios, it can be viewed as a summation projection algorithm. An example is presented of a computationally efficient 3-D line segment detector that uses maximum value projection. The algorithm is useful for optically detecting meteors, satellites, and other moving targets that move in a straight path across many frames of data. >
A Perspective Distilled from Seventy Years of Research

Physical organic chemistry might be regarded as officially recognized as a distinct discipline through the publication of L. P. Hammett’s book of that title, although substantial earlier work can be traced back to the turn of the 20th century. Many of the instrumental tools that helped the discipline develop in so many different ways began to appear in the late thirties and during World War II and were soon built to be increasingly operated in the “hands-on” mode. This development became very popular in academia, where instruments are not operated for you by an expert, but even if you are an undergraduate, you can more or less be the expert yourself and take many varieties of data on instruments usually available on a 24 h basis. It has been my privilege and joy to begin research in chemistry just as these waves of change began to grow and to savor the great contribution that the new methods, such as measurement of 14C, UV−vis, IR, NMR, and hands-on use of computers, made in facilitating our research programs at MIT and later at Caltech. Among those programs, which will be discussed, were 14C tracing of carbocation rearrangements and benzyne formation, electrical effects of substituents, Grignard reagents, synthesis of small-ring compounds, (2 + 2) cycloaddition reactions of halogenated ethylenes, assisting in development of ^(19)F, ^(13)C, and ^(15)N NMR for conformational analysis, other structural, kinetic, and tracer studies, as well as helping through textbooks to bring Huckel MO theory and the elements of NMR to familiarity for organic chemists. From the very beginning of my research career, I have been the beneficiary of personal mentoring which has been very crucial to my success in research and is an important theme in what follows.
A Neptune-Mass Planet Orbiting the Nearby M Dwarf GJ 436

We report precise Doppler measurements of GJ 436 (M2.5 V) obtained at Keck Observatory. The velocities reveal a planetary companion with orbital period of 2.644 days, eccentricity of 0.12 (consistent with zero), and velocity semiamplitude of K = 18.1 m s-1. The minimum mass (M sin i) for the planet is 0.067MJup = 1.2MNep = 21MEarth, making it the lowest mass exoplanet yet found around a main-sequence star and the first candidate in the Neptune-mass domain. GJ 436 (mass = 0.41 M☉) is only the second M dwarf found to harbor a planet, joining the two-planet system around GJ 876. The low mass of the planet raises questions about its constitution, with possible compositions of primarily H and He gas, ice/rock, or rock-dominated. The implied semimajor axis is a = 0.028 AU = 14 stellar radii, raising issues of planet formation, migration, and tidal coupling with the star. GJ 436 is more than 3 Gyr old, based on both kinematic and chromospheric diagnostics. The star exhibits no photometric variability on the 2.644 day Doppler period to a limiting amplitude of 0.0004 mag, supporting the planetary interpretation of the Doppler periodicity. Photometric transits of the planet across the star are ruled out for gas giant compositions and are also unlikely for solid compositions. As the third closest known planetary system, GJ 436 warrants follow-up observations by high-resolution optical and infrared imaging and by the Space Interferometry Mission.
Lorentz transformation and vector field flows

The parameter changes resulting from a combination of Lorentz transformations are shown to form vector field flows. The exact, finite Thomas rotation angle is determined and interpreted intuitively. Using phase portraits, the parameters evolution can be clearly visualized. In addition to identifying the fixed points, we obtain an analytic invariant which correlates the evolution of parameters.
Reliable Traffic Sensor Deployment Under Probabilistic Disruptions and Generalized Surveillance Effectiveness Measures

Sensor systems as critical components of a transportation network provide a variety of real-time traffic surveillance information for traffic management and control. The deployment of sensors significantly affects their overall surveillance effectiveness. This paper proposes a reliable sensor location model to optimize surveillance effectiveness when sensors are subject to site-dependent probabilistic failures, and a general effectiveness measure is proposed to encompass most existing measures needed for engineering practice e.g., flow volume coverage, vehicle-mile coverage, and squared error reduction. The problem is first formulated into a compact mixed-integer program, and we develop a variety of solution algorithms including a custom-designed Lagrangian relaxation algorithm and analyze their properties. We also propose alternative formulations including a continuum approximation model for single corridor problems and reliable fixed-charge sensor location models. Numerical case studies are conducted to test the performance of the proposed algorithms and draw managerial insights on how different parameter settings e.g., failure probability and spatial heterogeneity affect overall surveillance effectiveness and the optimal sensor deployment.
Selective deprotection of either alkyl or aryl silyl ethers from aryl, alkyl bis-silyl ethers

Abstract A pair of complementary methods was developed using CeCl 3 ·7H 2 O/CH 3 CN and LiOH/DMF to selectively deprotect alkyl and aryl silyl ethers, respectively, from the corresponding bis-silyl ethers in excellent yields.
Fundamental-mode rf design in e + e − storage ring factories

The difficulties arising in the design of the rf system for a factory-type storage ring lie mainly in two areas. First, a gap in the circulating beam current (on the order of 5% of the ring circumference) is required for ion clearing. Because of the high beam loading current, this gap produces a strong transient variation in the rf cavity voltage, which can in turn lead to a significant shift in the synchronous phases between bunches on either side of the gap. This phase shift would produce an unacceptable shift in the collision point, unless compensated by a corresponding shift in the bunch phases in the other ring. In order to work out the details of this compensation, the transient beam loading effects produced by the gap must be calculated quite carefully. A major goal of this chapter is to provide the insight and the basic analytic tools necessary for this analysis.
Strings and the holographic description of asymptotically de Sitter spaces

Asymptotically de Sitter spaces can be described by euclidean boundary theories with entropies given by the modified Cardy-Verlinde formula. We show that the Cardy-Verlinde formula describes a string with a rescaled tension which in fact is a string at the stretched cosmological horizon as seen from the boundary. The temperature of the boundary theory is the rescaled Hagedorn temperature of the string. Our results agree with an alternative description of asymptotically de Sitter spaces in terms of strings on the stretched horizon. The relation between the two descriptions is given by the large gravitational redshift between the boundary and the stretched horizon and a shift in energy.
Theory of radiation from low velocity shock heated air

Application of hypersonic computational fluid dynamics models to low velocity vehicles is examined. Important modeling aspects such as chemical kinetics, electronic excitation/de-excitation mechanisms, and existence of equilibrium vs nonequilibrium conditions in the flow were examined. Flowfield properties and in-band radiances in the wavelength region of 0.25 /i in the vicinity of the stagnation streamline are given for a hemisphere with a radius of 0.0762 m. Comparison with recent shock tube data is also shown.
Interactive privacy via the median mechanism

We define a new interactive differentially private mechanism --- the median mechanism --- for answering arbitrary predicate queries that arrive online. Given fixed accuracy and privacy constraints, this mechanism can answer exponentially more queries than the previously best known interactive privacy mechanism (the Laplace mechanism, which independently perturbs each query result). With respect to the number of queries, our guarantee is close to the best possible, even for non-interactive privacy mechanisms. Conceptually, the median mechanism is the first privacy mechanism capable of identifying and exploiting correlations among queries in an interactive setting.We also give an efficient implementation of the median mechanism, with running time polynomial in the number of queries, the database size, and the domain size. This efficient implementation guarantees privacy for all input databases, and accurate query results for almost all input distributions. The dependence of the privacy on the number of queries in this mechanism improves over that of the best previously known efficient mechanism by a super-polynomial factor, even in the non-interactive setting.
Restructuring institutional block trading: an overview of the OptiMark system

Financial markets perform many functions, but principal among them is to bring buyers and sellers together and provide a mechanism for price discovery. Information technology has had a number of significant impacts on financial markets, enabling enormous increases in volumes and more sophisticated trading techniques such as program trading and index arbitrage. Despite improvements, some large institutional investors identify shortcomings in today's markets that make the process of buying or selling large, block orders time-consuming and costly. To address these concerns, a new trading system, OptiMark, has been built around several innovations including: a graphical user front-end for depicting trading preferences; and a back-end built on high-performance computers that process expressions of trading interest according to a price-setting algorithm intended to achieve superior outcomes for traders. OptiMark provides a means for more cost-effective block trading, and expects to contribute to regulatory objectives. This paper details the operations of OptiMark, examines its adoption potential, and assesses the impact it may have on block trading, broker-dealer intermediaries, and the equities markets.
Estimating the Costs of Revenue Deficiency Programs

This paper develops an approach to empirically demonstrate how the within-season distribution of U.S. domestic commodity support for corn differs between current-style approaches of support and revenue-based support. From a purely economic standpoint, the results show the revenue-based payment scenarios to be preferable at the national level to the uncoordinated forms of support currently in use, even in a situation where the annual mean payments are set equal across the support scenarios. For revenue-based support, the variability around the total expected annual payment is lower, and perhaps more importantly, the probability of high payments is lower. These results suggest advantages to this type of support, both in terms of lower budgetary uncertainty for producers and the Federal government and in meeting multilateral commitments for limiting spending on domestic commodity support.
Keep ballots secret: On the futility of social learning in decision making by voting

We show that social learning is not useful in a model of team binary decision making by voting, where each vote carries equal weight. Specifically, we consider Bayesian binary hypothesis testing where agents have any conditionally-independent observation distribution and their local decisions are fused by any L-out-of-N fusion rule. The agents make local decisions sequentially, with each allowed to use its own private signal and all precedent local decisions. Though social learning generally occurs in that precedent local decisions affect an agent's belief, optimal team performance is obtained when all precedent local decisions are ignored. Thus, social learning is futile, and secret ballots are optimal. This conclusion contrasts with typical studies of social learning because we include a fusion center rather than concentrating on the performance of the latest-acting agents.
Lexical analysis in schizophrenia: how emotion and social word use informs our understanding of clinical presentation.

Background: The words people use convey important information about internal states, feelings, and views of the world around them. Lexical analysis is a fast, reliable method of assessing word use that has shown promise for linking speech content, particularly in emotion and social categories, with psychopathological symptoms. However, few studies have utilized lexical analysis instruments to assess speech in schizophrenia. In this exploratory study, we investigated whether positive emotion, negative emotion, and social word use was associated with schizophrenia symptoms, metacognition, and general functioning in a schizophrenia cohort. Methods: Forty-six participants generated speech during a semi-structured interview, and word use categories were assessed using a validated lexical analysis measure. Trained research staff completed symptom, metacognition, and functioning ratings using semi-structured interviews. Results: Word use categories significantly predicted all variables of interest, accounting for 28% of the variance in symptoms and 16% of the variance in metacognition and general functioning. Anger words, a subcategory of negative emotion, significantly predicted greater symptoms and lower functioning. Social words significantly predicted greater metacognition. Conclusions: These findings indicate that lexical analysis instruments have the potential to play a vital role in psychosocial assessments of schizophrenia. Future research should replicate these findings and examine the relationship between word use and additional clinical variables across the schizophreniaspectrum.
Low-complexity detection by exploiting suboptimal detection order and subcarrier grouping for Multi-Layer MIMO-OFDM

By combining the transmit diversity and space multiplexing, the multi-layer multiple-input multiple-output orthogonal frequency division multiplexing (Multi-Layer MIMO-OFDM) system can exploit the potentials of both techniques. The transmit antennas are divided into several layers and each layer is encoded by a certain Multi-Antenna Coding. The antennas transmit OFDM signals in order to deal with frequency-selective fading. In addition to Exhaustive Detection which applies the same detection at each subcarrier independently, we exploit the subcarrier correlation to develop a subcarrier grouping based Low-Complexity Detection scheme. The subcarriers bound into the same group share the same Layer Detection Order which is obtained by the Post-Nulling Signal Power comparison at the center subcarrier of that group. The simulation results show that compared with Exhaustive Detection, the proposed Low-Complexity Detection scheme is capable of reducing 50.7% complexity with only 0.8dB performance degradation for 6x6 system, and reducing 60.7% complexity with about 1.0dB performance degradation for 8x8 system, respectively.
Nonlinear instantons from supersymmetric p-branes

Supersymmetric configurations of type II D-branes with nonzero gauge field strengths in general supersymmetric backgrounds with nonzero B fields are analyzed using the kappa-symmetric worldvolume action. It is found in dimension four or greater that the usual instanton equation for the gauge field obtains a nonlinear deformation. The deformation is parameterized by the topological data of the B-field, the background geometry and the cycle wrapped by the brane. In the appropriate dimensions, limits and settings these equations reduce to deformed instanton equations recently found in the context of noncommutative geometry as well as those following from Lagrangians based on Bott-Chern forms. We further consider instantons comprised of M5-branes wrapping a Calabi-Yau space with non-vanishing three-form field strengths. It is shown that the instanton equations for the three-form are related to the Kodaira-Spencer equations.
Synchronization of wave-pipelined circuits

We investigate the synchronization schemes of wave-pipelined circuits. Previous analysis of valid clocking in wave-pipelined circuits is discussed and an intentional clock skew is introduced between the input and output registers as a function of the timing parameters of the wave-pipelined circuit, registers, and clock period. It is shown that, a clock skew value can be determined from the circuit information to achieve expected valid clock speed within the range bounded only by the basic timing constraints of wave pipelining. This is illustrated by applying the clock skew models to a 16-bit wave-pipelined adder designed using Wave-pipelined Transmission-Gate Logic (WTGL) technique. The results confirm the timing analysis. General clocking strategies of wave-pipelined systems are also discussed. >
Axion couplings and effective cut-offs in superstring compactifications

Abstract We use the linear supermultiplet formalism of supergravity to study axion couplings and chiral anomalies in the context of field-theoretical lagrangians describing orbifold compactifications beyond the classical approximation. By matching amplitudes computed in the effective low-energy theory with the results of string loop calculations we determine the appropriate counterterm in this effective theory that assures modular invariance to all loop order. We use supersymmetry consistency constraints to identify the correct ultraviolet cut-offs for the effective low-energy theory. Our results have a simple interpretation in terms of two-loop unification of gauge coupling constants at the string scale.
Synthesis of medicinally relevant terpenes: reducing the cost and time of drug discovery

Terpenoids constitute a significant fraction of molecules produced by living organisms that have found use in medicine and other industries. Problems associated with their procurement and adaptation for human use can be solved using chemical synthesis, which is an increasingly economical option in the modern era of chemistry. This article documents, by way of individual case studies, strategies for reducing the time and cost of terpene synthesis for drug discovery. A major trend evident in recent syntheses is that complex terpenes are increasingly realistic starting points for both medicinal chemistry campaigns and large-scale syntheses, at least in the context of the academic laboratory, and this trend will likely penetrate the commercial sector in the near future.
Advancing tests of relativistic gravity via laser ranging to Phobos

Phobos Laser Ranging (PLR) is a concept for a space mission designed to advance tests of relativistic gravity in the solar system. PLR’s primary objective is to measure the curvature of space around the Sun, represented by the Eddington parameter γ, with an accuracy of two parts in 107, thereby improving today’s best result by two orders of magnitude. Other mission goals include measurements of the time-rate-of-change of the gravitational constant, G and of the gravitational inverse square law at 1.5-AU distances—with up to two orders-of-magnitude improvement for each. The science parameters will be estimated using laser ranging measurements of the distance between an Earth station and an active laser transponder on Phobos capable of reaching mm-level range resolution. A transponder on Phobos sending 0.25-mJ, 10-ps pulses at 1 kHz, and receiving asynchronous 1-kHz pulses from earth via a 12-cm aperture will permit links that even at maximum range will exceed a photon per second. A total measurement precision of 50 ps demands a few hundred photons to average to 1-mm (3.3 ps) range precision. Existing satellite laser ranging (SLR) facilities—with appropriate augmentation—may be able to participate in PLR. Since Phobos’ orbital period is about 8 h, each observatory is guaranteed visibility of the Phobos instrument every Earth day. Given the current technology readiness level, PLR could be started in 2011 for launch in 2016 for 3 yr of science operations. We discuss the PLR’s science objectives, instrument, and mission design. We also present the details of science simulations performed to support the mission’s primary objectives.
Design and experimental studies of a generalized bilateral controller for a teleoperator system with a six DOF master and a seven DOF slave

Generalized bilateral control in teleoperation enables scaling, indexing, impedance control, shared control and the ability to use a non-replica master slave system. In this paper, control laws for both master and slave are derived for a desired impedance of the teleoperator system. A teleoperator system with six-degree-of-freedom Kraft hand controller (master) and a seven-degree-of-freedom Robotics Research Corporation manipulator (slave), is used as a testbed for generalized bilateral control. Parameter selection guidelines for the controller design are developed based on experimental studies of the teleoperator system. An assembly task is performed to test the effectiveness of the controller design. >
Self-organizing photorefractive frequency demultiplexer.

We demonstrate a self-organizing photorefractive circuit that demultiplexes a beam that has two signals imposed on separate optical carrier frequencies into two beams, each containing one of the signals on its carrier. Unlike conventional demultiplexing techniques, this method requires little a priori knowledge about the carrier frequencies. The signal channels must be spatially uncorrelated, and their frequency separation must be more than the photorefractive response bandwidth (hertz to kilohertz). The optical circuit uses no local oscillator, and the photorefractive response bandwidth places no upper bound on the channel bandwidth. Experimental results for demultiplexing a beam that has two signals, with a BaTiO3 circuit, show contrast ratios of better than 40:1 at the outputs.
Endogenous Preferences, Environmental Law

The rise of behavioral economics has important implications for the study of government regulation. Above all, the endogeneity of preferences offers a large area for positive work. Some environmental outcomes can be explained by status quo bias and the endowment effect. These phenomena help account for the asymmetry between old and new risks and the public antipathy toward strategies that create incentives to decrease use of automobiles. Both private and public behavior in the environmental context are an outgrowth of the fact that environmental preferences are endogenous to available opportunities, to shifting social norms, and to past acts of consumption.
The effect of institutional regime change within the new deal on industrial output and labor markets

Abstract Markets during the New Deal operated under a number of different institutional regimes, which were marked by executive orders, the passage of various pieces of legislation, and Supreme Court rulings on their constitutionality. Specifically, we break the New Deal period into the following six regimes: the Hundred Days, the President's Reemployment Agreement, the National Recovery Administration Codes of Fair Competition, the Schechter era, the National Labor Relations Act, and the Fair Labor Standards Act. Under these various regimes industrial markets were subject to different regulations relating to hourly wage rates, hours of work, the nature of competition, and unionization. Vector Autoregressive (VAR) regressions are run using a monthly panel of employment, weekly hours worked, wage rates, prices, and output for 11 major industries. We find that key policy and legal changes were associated with large and statistically significant movements in economic variables. Furthermore, changes in institutional regimes impacted different types of industries unevenly. For example, low-wage industries saw the largest increases in wages, and drops in output, after the mandated wage increases in 1933.
Magnetized Accretion inside the Marginally Stable Orbit around a Black Hole

Qualitative arguments are presented in order to demonstrate that the energy density of magnetic fields in matter accreting onto a black hole inside the marginally stable orbit is automatically comparable to the rest-mass energy density of the accretion flow. Several consequences follow: magnetic effects must be dynamically significant but cannot be so strong as to dominate; the outward energy transport in Alfven waves may alter the effective efficiency of energy liberation; and vertical magnetic stresses in this region may contribute to "coronal" activity.
Financial Markets can be at Sub-Optimal Equilibria

We use game theory and Santa Fe Artificial Stock Market, an agent-based model of an evolving stock market, to study the optimal frequency for traders to revise their market forecasting rules. We discover two things: There is a unique strategic Nash equilibrium in the game of choosing forecast revision rates, and this equilibrium is sub-optimal in the sense that traders' earnings are not maximized an the market is inefficient. This strategic equilibrium is due to an analogue of the prisoner's dilemma; the optimal global state is unstable because each trader has too much incentive to `defect' and use forecasting rules that pull the market into thesub-optimal equilibrium.
Automatic Synthesis of Efficient Intrusion Detection Systems on FPGAs

This paper presents a methodology and a tool for automatic synthesis of highly efficient intrusion detection systems using a high-level, graph-based partitioning methodology and tree-based lookahead architectures. Intrusion detection for network security is a compute-intensive application demanding high system performance. The tools implement and automate a customizable flow for the creation of efficient field programmable gate array (FPGA) architectures using system-level optimizations. Our methodology allows for customized performance through more efficient communication and extensive reuse of hardware components for dramatic increases in area-time performance
The cost of juvenile-onset recurrent respiratory papillomatosis

Objective To assess the medical costs and the number of quality-adjusted life years lost owing to juvenile-onset recurrent respiratory papillomatosis (JORRP). Design We examined hospital and physician charges for JORRP surgical procedures in Maryland in 1994 adjusting for inflation and the cost-charge ratio. Centers for Disease Control and Prevention data on treatment intensity for JORRP were augmented with a review of treatment records for 18 patients with JORRP. Sensitivity analyses were performed. To illustrate the application of our cost estimates, we compare the costs of JORRP to the costs of the surgical procedures that would be necessary to prevent it. Results We find that the present value at birth of the cost of a single case of JORRP is $201,724 (range, $61,822-$474,334). The annual cost for a single case of JORRP is $57,996 (range, $32,407-$94,114). The annual cost of JORRP in the United States is between $40 million and $123 million depending on the prevalence. Cesarean section (CS) for women with condyloma has been suggested as a potential strategy to prevent JORRP, but its efficacy remains to be determined. Our results suggest that if only 1% of the CSs actually prevented JORRP, this strategy would be a cost-effective means to prevent JORRP. Conclusions Studies to reduce the uncertainty surrounding the efficacy of CS and the effect of both CS and JORRP on families need to precede consideration of a policy of CS for women with clinically evident genital condyloma. Patients should be kept thoroughly informed about the role of CS for the prevention of JORRP and the nature of the remaining uncertainties.
SUSY vs E8 gauge theory in 11 dimensions

Diaconescu, Moore and Witten have shown that the topological part of the M-theory partition function is an invariant of an E8 gauge bundle over the 11-dimensional bulk. Any construction of 11d SUGRA from gauge bundle data must satisfy a number of constraints in order to correctly reproduce the the known 10-dimensional physics on each boundary component. We analyse these constraints and in particular use them to attempt an approximate construction of the 11d gravitino as a condensate of the gauge theory fields.
Announced Retransmission Random Access Protocols

A new contention-based broadcast multiaccess protocol called announced retransmission random access (ARRA) is introduced and analyzed in this paper. The proposed class of protocols increases the capacity of a slotted random access channel by adding a small amount of potentially useful control information to every message transmission. In particular, the ARRA technique requires users to announce the intended location of their potential retransmission slot (to be used in the event of a collision) over a low-rate announcement subchannel, so that conflicts between new and retransmitted messages can be prevented. The proposed protocols provide significant capacity improvements over conventional contention protocols, without sacrificing the simplicity and operational convenience associated with random access. It is shown that with a modest amount of processing and storage at the terminals, capacities in the range of 0.5-0.6 can be achieved, as compared with 0.37 for slotted ALOHA and 0.4-0.5 for the more efficient tree algorithm-based collision resolution algorithms (CRA's). Specifically, the basic ARRA protocol, in which announced retransmissions take place unconditionally, has a capacity of about 0.53. An improved algorithm (called extended ARRA), which involves aborting predictably unsuccessful retransmissions, has a capacity of 0.6. In addition, because of delay considerations, the proposed ARRA protocols are well suited for operation on satellite channels.
An algebraic approach to network coding

We take a new look at the issue of network capacity. It is shown that network coding is an essential ingredient in achieving the capacity of a network. Building on recent work by Li et al.(see Proc. 2001 IEEE Int. Symp. Information Theory, p.102), who examined the network capacity of multicast networks, we extend the network coding framework to arbitrary networks and robust networking. For networks which are restricted to using linear network codes, we find necessary and sufficient conditions for the feasibility of any given set of connections over a given network. We also consider the problem of network recovery for nonergodic link failures. For the multicast setup we prove that there exist coding strategies that provide maximally robust networks and that do not require adaptation of the network interior to the failure pattern in question. The results are derived for both delay-free networks and networks with delays.
Geometric parameters in nucleic acids: Nitrogenous bases

We present estimates of the bond-length and bond-angle parameters for the nitrogenous base side groups of nucleic acids. These values are the result of a statistical survey of small molecules in the Cambridge Structural Database for which high-resolution X-ray and neutron crystal structures are available. The statistics include arithmetic means and standard deviations for the different samples, as well as comparisons of the population distributions for sugar- and non-sugar-derivatized bases. These accumulated data provide appropriate target values for refinements of oligonucleotide structures, as well as sets of standard atomic coordinates for the five common bases.
Simultaneous, maximum-likelihood determination of focal length and source position for point-source experiments with pinhole collimation

A simple procedure to determine the focal length of a pinhole collimator is presented, which is important for planar and SPECT imaging. The procedure involves the use of a point source and three linear stages. The source is moved by carefully controlled relative shifts in two dimensions to a number of different positions within a plane nearly perpendicular to the detector's plane. For each position a projection is acquired. The focal length is calculated from the shift in the centroid of the projections via a maximum-likelihood fit. A useful byproduct of the procedure is calibration of the position of the source, which can then be used for planar imaging studies such as sensitivity and point-spread function. This calibration maps the coordinate system of the stages to the coordinate system of the aperture. The method was experimentally validated for three different focal lengths.
EFFECTS OF FREE-END BOUNDARY CONDITION ON THE FREQUENCY SPECTRUM OF A VICSEK FRACTAL

In this paper, we investigate the effects of free-end boundary condition on the transverse vibrations of a Vicsek fractal. The unique feature of the eigenvalue spectrum corresponding to this case is that both non-degenerate and degenerate modes of a given generation are present in all subsequent generations, whereas in the case of fixed-end boundary condition only the degenerate modes persist. In the first case, the nature of the persistent degenerate modes is found to be either edge-localized or localized in the region between two adjacent clusters or adjacent sub-clusters, whereas in the second case the persistent modes are found to be edge-confined superlocalized modes. In both cases one finds that: (i) the frequency spectrum consists of atomic-like levels superimposed on a point-dense, cantor-set-like background; and (ii) there is side-by-side coexistence of the extended non-degenerate modes and superlocalized degenerate persistent modes.
Inference of Finite Automata Using Homing Sequences

Abstract We present new algorithms for inferring an unknown finite-state automaton from its input/output behavior, even in the absence of a means of resetting the machine to a start state. A key technique used is inference of a homing sequence for the unknown automaton. Our inference procedures experiment with the unknown machine, and from time to time require a teacher to supply counterexamples to incorrect conjectures about the structure of the unknown automaton. In this setting, we describe a learning algorithm that, with probability 1 − δ, outputs a correct description of the unknown machine in time polynomial in the automaton′s size, the length of the longest counterexample, and log(1/δ). We present an analogous algorithm that makes use of a diversity-based representation of the finite-state system. Our algorithms are the first which are provably effective for these problems, in the absence of a "reset." We also present probabilistic algorithms for permutation automata which do not require a teacher to supply counterexamples. For inferring a permutation automaton of diversity D, we improve the best previous time bound by roughly a factor of D3/log D.
Structure of defective crystals at finite temperatures: A quasi-harmonic lattice dynamics approach

Abstract In this paper we extend the classical method of lattice dynamics to defective crystals with partial symmetries. We start by a nominal defect configuration and first relax it statically. Having the static equilibrium configuration, we use a quasi-harmonic lattice dynamics approach to approximate the free energy. Finally, the defect structure at a finite temperature is obtained by minimizing the approximate Helmholtz free energy. For higher temperatures we take the relaxed configuration at a lower temperature as the reference configuration. This method can be used to semi-analytically study the structure of defects at low but non-zero temperatures, where molecular dynamics cannot be used. As an example, we obtain the finite temperature structure of two 180° domain walls in a 2D lattice of interacting dipoles. We dynamically relax both the position and polarization vectors. In particular, we show that increasing temperature the domain wall thicknesses increase.
Two-Component Jet Models of Gamma-Ray Burst Sources

Recent observational and theoretical studies have raised the possibility that the collimated outflows in gamma-ray burst (GRB) sources have two distinct components: a narrow (opening half-angle {theta}{sub n}), highly relativistic (initial Lorentz factor {eta}{sub n} & 10{sup 2}) outflow, from which the {gamma}-ray emission originates, and a wider ({theta}{sub w} {approx} E{sub n}, as expected for the decoupled neutron and proton components, respectively, in an initially neutron-rich, hydromagnetically accelerated jet model, then the narrow component only dominates the early afterglow and the wide component takes over after its nominalmore » deceleration time t{sub dec,w} (typically {approx} 0.1-1 days). For characteristic parameter values t{sub dec,w} is comparable to the jet break time t{sub jet,n} of the narrow component. In this case the emergence of the wide component at t{sub dec,w} may mask the jet break in the narrow component at t{sub jet,n} if E{sub w} & E{sub n}, which in turn may lead to an overestimate of the {gamma}-ray energy emitted by the source and hence of the required {gamma}-ray emission efficiency. We apply this scheme also to X-ray flash sources, which we interpret as GRB jets viewed at an angle {theta}{sub obs} > {theta}{sub n}. Finally, we argue that a neutron-rich hydromagnetic outflow may naturally give rise to repeated brightening episodes in the afterglow lightcurve as observed in GRB 021004 and GRB 030329.« less
Derivation of Calabi-Yau crystals from Chern-Simons gauge theory

We derive new crystal melting models from Chern-Simons theory on the three-sphere. Via large N duality, these models compute amplitudes for A-model on the resolved conifold. The crystal is bounded by two walls whose distance corresponds to the Kahler modulus of the geometry. An interesting phenomenon is found where the Kahler modulus is shifted by the presence of non-compact D-branes. We also discuss the idea of using the crystal models as means of proving more general large N dualities to all order in g(s).