cssi/SciSciGPT-SciSciNet huggingface dataset:
Interference channels with strong secrecy

It is known that given the real sum of two independent uniformly distributed lattice points from the same nested lattice codebook, the eavesdropper can obtain at most 1 bit of information per channel regarding the value of one of the lattice points. In this work, we study the effect of this 1 bit information on the equivocation expressed in three commonly used information theoretic measures, i.e., the Shannon entropy, the Renyi entropy and the min entropy. We then demonstrate its applications in an interference channel with a confidential message. In our previous work, we showed that nested lattice codes can outperform Gaussian codes for this channel when the achieved rate is measured with the weak secrecy notion. Here, with the Renyi entropy and the min entropy measure, we prove that the same secure degree of freedom is achievable with the strong secrecy notion as well. A major benefit of the new coding scheme is that the strong secrecy is generated from a single lattice point instead of a sequence of lattice points. Hence the mutual information between the confidential message and the observation of the eavesdropper decreases much faster with the number of channel uses than previously known strong secrecy coding methods for nested lattice codes.
PHYSICAL FITNESS AND CARDIOVASCULAR DISEASE MORTALITY THE US RAILROAD STUDY

The relation between physical fitness and cardiovascular disease mortality was examined in US railroad workers, as a part of the Seven Countries Study. A cohort of 3,043 white, middle-aged men initially aged 22-79 years were first examined in 1957-1960 and re-examined in 1962-1964. Men with clinically diagnosed cardiovascular disease (n = 465) were excluded from this study. This cohort was followed until death or 1977. Mortality was monitored through the Railroad Retirement Board. Physical fitness was ascertained by a sub-maximal treadmill test administered in a Pullman Car converted to a survey laboratory. Exercise heart rate was directly and significantly related to coronary heart disease mortality, cardiovascular disease mortality, and all-cause mortality after adjusting for age. These relations were greatly attenuated when adjusted for blood pressure level. The risk for coronary heart disease when an exercise test heart rate of 135 beats per minute was compared with a rate of 105 beats per minute was 1.43, after adjusting for age, and 1.20, after adjusting for blood pressure, serum cholesterol levels, and smoking, as well as age. Results from this study suggest that middle-aged men with lower levels of physical fitness, as shown by higher sub-maximal exercise test heart rates, are at greater risk of dying of coronary heart disease, cardiovascular disease, and all causes in an average follow-up of 20 years. This greater risk is largely due to higher blood pressure levels.
Chemical ecology of the marine plankton.

Covering: October 2010 to December 2012. Previous review Nat. Prod. Rep. 2011, 28, 388–399This review summarizes recent work in the chemical ecology of pelagic marine ecosystems. In order to provide a comprehensive overview of advances in the field over the period covered, we have organized this review by ecological interaction type beginning with intraspecific interactions, then interspecific interactions (including mutualism, parasitism, competition, and predation), and finally community- and ecosystem-wide interactions.
Synthesis of SAPO-34 Crystals in the Presence of Crystal Growth Inhibitors

Microporous SAPO-34 molecular sieves were synthesized employing polyethylene glycol, polyoxyethylene lauryl ether, and methylene blue as crystal growth inhibitors. The synthesized SAPO-34 crystals displayed BET surface areas up to 700 m2/g, high CO2/CH4 adsorption ratios, and small crystal size in the approximately 0.6-0.9 microm range with narrow particle size distribution. The enhanced CO2/CH4 adsorption capacities were related to the high N/H ratios observed in the phases prepared in the presence of crystal growth inhibitors. The synthesized SAPO-34 crystals may find potential applications to prepare membranes for CO2 purification.
Fast batch verification for modular exponentiation and digital signatures

Many tasks in cryptography (e.g., digital signature verification) call for verification of a basic operation like modular exponentiation in some group: given (g, x, y) check that gx = y. This is typically done by re-computing gx and checking we get y. We would like to do it differently, and faster.
Building programmable wireless networks: an architectural survey

In recent times, there is increasing consensus that the traditional Internet architecture needs to be evolved for it to sustain unstinted growth and innovation. A major reason for the perceived architectural ossification is the lack of the ability to program the network as a system. This situation has resulted partly from historical decisions in the original Internet design which emphasized decentralized network operations through colocated data and control planes on each network device. The situation for wireless networks is no different resulting in a lot of complexity and a plethora of largely incompatible wireless technologies. With traditional architectures providing limited support for programmability, there is a broad realization in the wireless community that future programmable wireless networks would require significant architectural innovations. In this paper, we will present an unified overview of the programmability solutions that have been proposed at the device and the network level. In particular, we will discuss software-defined radio (SDR), cognitive radio (CR), programmable MAC processor, and programmable routers as device-level programmability solutions, and software-defined networking (SDN), cognitive wireless networking (CWN), virtualizable wireless networking (VWN) and cloud-based wireless networking (CbWN) as network-level programmability solutions. We provide both a self-contained exposition of these topics as well as a broad survey of the application of these trends in modern wireless networks.
A policy note on telecommunications reform in Algeria

By the end of the 1990s, most developed and many developing countries had liberalized their telecommunications markets to improve service accessibility and affordability to both businesses and households. In contrast, Algeria still managed its telecommunications sector as public property. The Ministry of Post and Telecommunications set the policy, enforced regulation and was in charge of service provision. The sector suffered from huge supply shortages, the waiting list lengthened, the quality of service deteriorated and overall the fiscal situation was unbalanced. In 1999, a new government appointed in the aftermath of President Bouteflika's election decided to change the situation and launched a comprehensive sector reform. This note reviews progress made in implementing this reform, discusses its preliminary impact, and comments on the main lessons learned. The note shows that by restraining arbitrary administrative action during the reform implementation, the government of Algeria laid the foundation for sustainable growth in the telecommunications sector.
Theory of fluctuations in a network of parallel superconducting wires

Abstract We show how the partition function of a network of parallel superconducting wires weakly coupled together by the proximity effect, subjected to a vector potential along the wires, can be mapped onto N -distinguishable two dimensional quantum-mechanics problem with a perpendicular imaginary magnetic field. Then, we show, using a mean field approximation, that, for a given coupling, there is a critical temperature for onset of inter-wire phase coherence. The transition temperature T c is plotted on both cases for non-magnetic and a magnetic field perpendicular to the wires.
The Quasi-Additivity Law in conformal geometry

On a Riemann surface S of nite type containing a family of N disjoint disks Di (\islands"), we consider several natural conformal invariants measuring the distance from the islands to @S and the separation between dierent islands. In a near degenerate situation we establish a relation between them called the Quasi-Additivity Law. We then generalize it to a Quasi-Invariance Law providing us with a transformation rule of the moduli in question under covering maps. This rule (and in particular, its special case called the Covering Lemma) has important applications in holomorphic dynamics.
Welfare Reform when Recipients Are Forward-Looking

In 1996 the Aid to Families with Dependent Children program was replaced with the Temporary Assistance for Needy Families (TANF) program. This paper considers the effects of two specific components of TANF, time limits and work requirements, on employment, marriage, and welfare participation. A discrete-choice dynamic programming model is used, and parameter estimates are obtained using data from the Panel Study of Income Dynamics. Policy simulations show that a five-year lifetime time limit results in a 60 percent reduction in welfare use and that a substantial part of this reduction occurs because recipients are forward-looking.
The Compression of Morbidity

In this century, we are progressing through three separate eras with dramatically different characteristics of health and illness. We entered the century in an era of infectious disease, with tuberculosis the number one killer of our population, and smallpox, diphtheria, tetanus, and other infectious illnesses extremely prevalent. A reduction in mortality from these diseases of over 99% (Fries and Crapo, 1981; Cooper, 1982), has led to the present era, where the major illness burdens of the United States are the chronic diseases. Atherosclerosis and its complications, neoplasia, emphysema, diabetes, cirrhosis, and osteoarthritis have increased in prevalence even as the infectious illnesses which preceded them declined. It is one thesis of this discussion that this chronic disease era in its turn will slowly decline in significance, leaving a third era in which major health problems of the United States will be directly related to the process of senescence, and where the aging process itself, independent of specific disease, will constitute a major illness burden for the United States.
Yang-Mills theory and the Segal-Bargmann transform

We use a variant of the Segal-Bargmann transform to study canonically quantized Yang-Mills theory on a space-time cylinder with a compact structure group K. The non-existent Lebesgue measure on the space of connections is "approximated" by a Gaussian measure with large variance. The Segal-Bargmann transform is then a unitary map from the L 2 space over the space of connections to a holomorphicL 2 space over the space of complexified connections with a certain Gaussian measure. This transform is given roughly bye t1A=2 followed by analytic continuation. Here 1A is the Laplacian on the space of connections and is the Hamiltonian for the quantized theory. On the gauge-trivial subspace, consisting of functions of the holonomy around the spatial circle, the Segal-Bargmann transform becomes e t1 K=2 followed by analytic continuation, where 1K is the Laplacian for the structure group K. This result gives a rigorous meaning to the idea that 1A reduces to 1K on functions of the holonomy. By letting the variance of the Gaussian measure tend to infinity we recover the standard realization of the quantized Yang-Mills theory on a space-time cylinder, namely, 1 1K is the Hamiltonian and L 2 (K) is the Hilbert space. As a byproduct of these considera- tions, we find a new one-parameter family of unitary transforms from L 2 (K) to certain holomorphicL 2 -spaces over the complexification of K. This family of transformations interpolates between the two previously known unitary transformations. Our work is motivated by results of Landsman and Wren and uses probabilistic techniques similar to those of Gross and Malliavin.
A Conversation with Robert V. Hogg

Robert Vincent Hogg was born on November 8, 1924 in Hannibal, Missouri. He earned a Ph.D. in statistics at the University of Iowa in 1950, where his advisor was Allen Craig. Following graduation, he joined the mathematics faculty at the University of Iowa. He was the founding Chair when the Department of Statistics was created at Iowa in 1965 and he served in that capacity for 19 years. At Iowa he also served as Chair of the Quality Management and Productivity Program and the Hanson Chair of Manufacturing Productivity. He became Professor Emeritus in 2001 after 51 years on the Iowa faculty. He is a Fellow of the Institute of Mathematical Statistics and the American Statistical Association plus an Elected Member of the International Statistical Institute. He was President of the American Statistical Association (1988) and chaired two of its winter conferences (1992, 1994). He received the ASA’s Founder’s Award (1991) and the Gottfried Noether Award (2001) for contributions to nonparametric statistics. His publications through 1996 are described in Communications in Statistics—Theory and Methods (1996), 2467–2481. This interview was conducted on April 14, 2004 at the Department of Statistics, University of Florida, Gainesville, Florida, and revised in the summer of 2006.
On the fluorescence from integrating spheres

Our recent study of the performance of integrating spheres shows prominent UV induced fluorescence features that are associated with contamination of the diffusing wall material by hydrocarbons. Because of multiple reflections of the radiation inside the integrating sphere, fluorescence is induced multiple times with each reflection of the incident radiation by the wall. Here, we report a simple theory on the fluorescence of integrating spheres developed from first principles. The results indicate a strong dependence of fluorescence on the reflectance of the diffusing material at both the excitation and fluorescence wavelengths as well as the geometry of the integrating sphere. Because of multiple reflection of the exciting radiation, a gain of more than an order of magnitude in fluorescence is possible compared with direct and single irradiation of a flat piece of the diffusing/fluorescing material. Applications of such fluorescence analysis for integrating spheres are discussed.
The Diurnal Cycle of Precipitation in Tropical Cyclones

AbstractPosition and intensity data from the International Best Track Archive for Climate Stewardship (IBTrACS) are combined with global, gridded precipitation estimates from the Tropical Rainfall Measuring Mission (TRMM) Multisatellite Precipitation Analysis (TMPA) for the period 1998–2013 to study the diurnal cycle of precipitation in tropical cyclones. The comprehensive global coverage and large sample size afforded by the two datasets allow robust statistical analysis of storm-averaged diurnal variations and permit stratification of the data in various ways. There is a clearly detectable diurnal variation of precipitation in tropical cyclones with peak rainfall occurring near 0600 local time. For storms of all intensities the amplitude of the diurnal harmonic, which dominates the diurnal cycle, is approximately 7% of the mean rain rate. This corresponds to a peak-to-peak variation of about 15% over the course of the day. The diurnal cycle is similar in all ocean basins. There is evidence that the ampl...
The power of geometric duality

This paper uses a new formulation of the notion of duality that allows the unified treatment of a number of geometric problems. In particular, we are able to apply our approach to solve two long-standing problems of computational geometry: one is to obtain a quadratic algorithm for computing the minimum-area triangle with vertices chosen amongn points in the plane; the other is to produce an optimal algorithm for the half-plane range query problem. This problem is to preprocessn points in the plane, so that given a test half-plane, one can efficiently determine all points lying in the half-plane. We describe an optimalO(k + logn) time algorithm for answering such queries, wherek is the number of points to be reported. The algorithm requiresO(n) space andO(n logn) preprocessing time. Both of these results represent significant improvements over the best methods previously known. In addition, we give a number of new combinatorial results related to the computation of line arrangements.
On modeling program behavior

This is a paper about the history of the working set model for program behavior. It traces briefly the origins and bases of the idea and some of the results subsequently obtained. The physical context is a hierarchical memory system consisting of a severely limited quantity of main (directly-addressable) storage and an essentially unlimited quantity of secondary (backup) storage. In this context, the intuitive notion of "working information" as the set of words which are (or should be) loaded in main memory at any given time in order that a program may operate efficiently is as old as programming itself. The sharply increased interest in program models since the mid-1960s is a direct consequence of the widening use of virtual memory and multiprogramming techniques, which have shifted the responsibility of memory management from programmers to machines. I am assuming here that the purpose of memory management is ensuring that an active program's working information is present in main memory, and the purpose of a program model is providing a basis for determining a program's working information at a given time and predicting what it will be at a future time.
Leveraging Web services for information discovery

We describe a novel application of the Web services model for end-user information discovery needs rather than for the traditional business-to-business applications. We describe a specialization of Web services for information providers and demonstrate, through an exemplary unified information discovery console, how consumers can easily customize their favorite information sources, and obtain information from them in a passive or active but always unobtrusive manner.
The Impact of Eliminating the Form 20-F Reconciliation on Shareholder Wealth: Evidence from U.S. Cross-Listed Firms

ABSTRACT: This paper examines shareholder wealth effects in U.S. and home-country markets relating to the Securities and Exchange Commission's (SEC) decision to eliminate the Form 20-F reconciliation. During the period of examined events, we find positive cumulative abnormal returns for the treatment sample of U.S. cross-listed firms that prepare financial statements under International Financial Reporting Standards (IFRS), but no such effects for our control sample comprising cross-listed non-IFRS, U.S. domestic, or home-country firms. We find the stock market impact for our treatment sample to be positively related to our proxy for cost savings and negatively related to the pre-adoption reconciliation magnitude from IFRS to U.S. GAAP. This suggests shareholders place some value on reconciliation information, but the costs of preparing and auditing reconciliations generally outweigh concern about information loss. Moreover, we find that information loss is less pronounced for firms having used IFRS for a...
Dynamic Simulation of a Wave-Rotor-Topped Turboshaft Engine

The dynamic behavior of a wave-rotor-topped turboshaft engine is examined using a numerical simulation. The simulation utilizes an explicit, one-dimensional, multipassage, computational e uid dynamics- (CFD-) based wave-rotor code in combination with an implicit, one-dimensional, component-level dynamic engine simulation code. Transient responses to rapid fuel e ow rate changes and compressor inlet pressurechanges aresimulated and compared with those of a similarly sized, untopped, turboshaft engine. Resultsindicate that the wave-rotor-topped engine responds in a stable and rapid manner. Furthermore, during certain transient operations, the wave rotor actually tends to enhance engine stability. In particular, there is no tendency toward surge in the compressor of thewave-rotor-topped engine during rapid acceleration. In fact, thecompressor actually movesslightly away from the surge line during this transient. This behavior is precisely the opposite to that of an untopped engine. The simulation is described. Issues associated with integrating CFD and component-level codes are discussed. Results from several transient simulations are presented and discussed.
Technology, distribution and the rate of profit in the US economy: understanding the current crisis.

This paper offers a synoptic account of the state of the debate among Marxist scholars regarding the current structural crisis of capitalism, identifies two broad streams within the literature dealing, in turn, with aggregate demand and profitability problems, and proceeds to concentrate on an analysis of issues surrounding the profitability problem in two steps. First, evidence on profitability trends for the non-farm non-financial corporate business, the non-financial corporate business and the corporate business sectors in post-war USA are summarised. A broad range of profit rate measures are covered and data from both the US Bureau of Economic Analysis (NIPA and Fixed Assets Tables) and the Federal Reserve (Flow of Funds Account) are used. Second, the underlying drivers of profitability, in terms of technology and distribution, are investigated. The profitability analysis is used to offer some hypotheses about the current structural crisis. Copyright , Oxford University Press.
The Unexpected Impact of Information Sharing on US Pharmaceutical Supply Chains

This paper examines a change in business practices in the pharmaceutical manufacturer-to-distributor supply chain, a change that essentially forced pharmaceutical distributors to maintain lower inventories. This change also provided pharmaceutical manufacturers with information about distributor customer demand and inventories that had previously been withheld from them. Supply chain theory and practice in other industries suggest that by improving decision making and implementation, companies can operate with substantially lower inventories. This happened in pharmaceutical distribution when a Securities and Exchange Commission investigation led manufacturers to force distributors to operate with less inventory. Theory and practice further suggest that manufacturers who are provided with relevant information that they did not have previously would take advantage of this information to reduce their inventories. This evidently did not happen in pharmaceutical manufacturing. We contend that pharmaceutical manufacturers either do not know how to take advantage of such information or they do not care.
Intrinsic vs. Image-Related Utility in Social Media: Why Do People Contribute Content to Twitter?

We empirically study the motivations of users to contribute content to social media in the context of the popular microblogging site Twitter. We focus on noncommercial users who do not benefit financially from their contributions. Previous literature suggests that there are two main types of utility that motivate these users to post content: intrinsic utility and image-related utility. We leverage the fact that these two types of utility give rise to different predictions as to whether users should increase their contributions when their number of followers increases. To address the issue that the number of followers is endogenous, we conducted a field experiment in which we exogenously added followers or follow requests, in the case of protected accounts to a set of users over a period of time and compared their posting activities to those of a control group. We estimated each treated user's utility function using a dynamic discrete choice model. Although our results are consistent with both types of utility being at play, our model suggests that image-related utility is larger for most users. We discuss the implications of our findings for the evolution of Twitter and the type of value firms may derive from such platforms in the future.
A noncommutative symmetric system over the Grossman-Larson Hopf algebra of labeled rooted trees

In this paper, we construct explicitly a noncommutative symmetric ( ${\mathcal{N}}$ CS) system over the Grossman-Larson Hopf algebra of labeled rooted trees. By the universal property of the $\mathcal {N}$ CS system formed by the generating functions of certain noncommutative symmetric functions, we obtain a specialization of noncommutative symmetric functions by labeled rooted trees. Taking the graded duals, we also get a graded Hopf algebra homomorphism from the Connes-Kreimer Hopf algebra of labeled rooted forests to the Hopf algebra of quasi-symmetric functions. A connection of the coefficients of the third generating function of the constructed $\mathcal {N}$ CS system with the order polynomials of rooted trees is also given and proved.
Improved granular medium model for unconsolidated sands using coordination number, porosity, and pressure relations

We have developed a recipe for using closed-form expressions of effective-medium models to predict velocities in unconsolidated sandstones. The commonly used Hertz-Mindlin effective-medium model for granular media often predicts elastic wave velocities that are higher, and VP ∕ VS ratios that are lower, than those observed in laboratory and well log measurements in unconsolidated sediments. We use the extended Walton model, which introduces a parameter α to represent the fraction of grain contacts that are perfectly adhered. Using the extended Walton model with α ranging from 0.3 to 1, we obtain new empirical relations between the coordination number (C), porosity, and pressure for P- and S-wave velocities by inverting dynamic measurements on dry, unconsolidated sands. We propose using the extended Walton model (α=0.6) along with these new C-porosity and C-pressure relations to study the mechanical compaction of unconsolidated sandstones. The model has been tested on two experimental data sets. It provide...
Some personality correlates of decision making under conditions of risk

How does the personality of the decision maker affect the rules which guide his decisions? Does a gambler normally bet in such a way so as to maximize expected gain? What is the relation between the objective probability of the event and the way this probability appears to the risk taker? A combination of clinical psychological methods and statistical methods reveals some interesting relations among background, inferred personality traits, and observed gambling behavior of people.
Identification of standard auction models

This paper presents new identification results for models of first-price, second-price, ascending (English), and descending (Dutch) auctions. We consider a general specification of the latent demand and information structure, nesting both private values and common values models, and allowing correlated types as well as ex ante asymmetry. We address identification of a series of nested models and derive testable restrictions enabling discrimination between models on the basis of observed data. The simplest model-symmetric independent private values-is nonparametrically identified even if only the transaction price from each auction is observed. For richer models, identification and testable restrictions may be obtained when additional information of one or more of the following types is available: (i) the identity of the winning bidder or other bidders; (ii) one or more bids in addition to the transaction price; (iii) exogenous variation in the number of bidders; (iv) bidder-specific covariates. While many private values (PV) models are nonparametrically identified and testable with commonly available data, identification of common values (CV) models requires stringent assumptions. Nonetheless, the PV model can be tested against the CV alternative, even when neither model is identified.
Strings, monopoles, and gauge fields

The Nielsen-Olesen interpretation of dual strings as Abrikosov flux lines is extended to the case of open-ended strings by adapting Dirac's description of magnetic monopoles to a London-type theory. The mathematical formalism turns out to be similar to that of Kalb and Ramond. Translated to hadron physics, it implies that the quarks will act as carriers of magnetic charge, permanently bound in pairs by the string bonds. However, massive axial-vector gluons can be created by hadrons.
Stodolsky's theorem and neutrino oscillation phases-for pedestrians.

Neutrino oscillations are experimentally observable only as a result of interference between neutrino states with different masses and the same energy. All interference effects between neutrino states having different energies are destroyed by the interaction between the incident neutrino and the neutrino detector. Erroneous results are frequently obtained by neglecting the neutrino-detector interactions.
IP lookup by binary search on prefix length

Waldvogel et al. [ACM SIGCOMM, 1997, 25-36] have proposed a collection of hash tables (CHT) organization for an IP router table. IP lookup can be done with O(log l/sub dist/) hash-table searches, where l/sub dist/ is the number of distinct prefix-lengths (also equal to the number of hash tables in the CHT). Srinivasan and Varghese [ACM transactions on Computer Systems, Feb:1-40, 1999] have proposed the use of controlled prefix-expansion to reduce the value of l/sub dist/. The algorithm of [V. Srinivasan, 1999] does not minimize the storage required by the prefixes and markers for the resulting set of prefixes. We develop an algorithm that minimizes storage requirement but takes O(nW/sup 3/ + kW/sup 4/) time, where k is the desired number of distinct lengths, n is the number of prefixes, and W is the length of the longest prefix. Also, we propose improvements to the heuristic of [V. Srinivasan, 1999].
Impact evaluation of school feeding programs in Lao PDR

Despite the popularity and widespread implementation of school feeding programs, evidence of their impact on school participation and nutritional status is mixed. In this study the authors evaluate feeding programs in three districts of the Lao People's Democratic Republic (PDR). Feeding modalities included on-site feeding, take-home rations, and a combined modality. District-level implementation of the intervention sites and selective take-up presented considerable evaluation challenges. To address these, the authors use difference-indifference estimators with propensity-score weighting to construct plausible counterfactuals. The authors find minimal evidence that school feeding increased enrolment or improved nutritional status. Several robustness checks and possible explanations for null findings are presented.
An analysis of errors and their causes in system programs

Program errors detected during internal testing of the operating system DOS/VS form the basis for an investigation of error distributions in system programs. Using a classification of the errors according to various attributes, conclusions can be drawn concerning the possible causes of these errors. The information thus obtained is applied in a discussion of the most effective methods for the detection and prevention of errors.
Synthesis of ent-Thallusin

[reaction: see text] A three-step route from sclareol oxide (6) to bromo ester 4 in 53% overall yield was achieved using the efficient oxidation of an allylic bromide to an enal with bis(2,4,6-trimethylpyridine)silver(I) hexafluorophosphate in DMSO. Stille coupling of bromo ester 4 with stannylpyridine 5 gave the trimethyl ester of ent-thallusin in 54-92% yield by the stoichiometric conversion of 4 to a vinyl palladium intermediate prior to the addition of 5 to the reaction.
Inverse optimization techniques for targeted self-assembly

This article reviews recent inverse statistical-mechanical methodologies that we have devised to optimize interaction potentials in soft matter systems that correspond to stable “target” structures. We are interested in finding the interaction potential, not necessarily pairwise additive or spherically symmetric, that stabilizes a targeted many-body system by generally incorporating complete configurational information. Unlike previous work, our primary interest is in the possible many-body structures that may be generated, some of which may include interesting but known structures, while others may represent entirely new structural motifs. Soft matter systems, such as colloids and polymers, offer a versatile means of realizing the optimized interactions. It is shown that these inverse approaches hold great promise for controlling self-assembly to a degree that surpasses the less-than-optimal path that nature has provided. Indeed, we envision being able to “tailor” potentials that produce varying degrees of disorder, thus extending the traditional idea of self-assembly to incorporate both amorphous and crystalline structures as well as quasicrystals. The notion of tailoring potentials that correspond to targeted structures is motivated by the rich fundamental statistical-mechanical issues and questions offered by this fascinating inverse problem as well as our recent ability to identify structures that have optimal bulk properties or desirable performance characteristics. Recent results have already led to a deeper basic understanding of the mathematical relationship between the collective structural behavior of many-body systems and their interactions, as well as optimized potentials that enable self-assembly of ordered and disordered particle configurations with novel structural and bulk properties.
Outage Analysis of Block-Fading Gaussian Interference Channels

This paper considers the asymptotic behavior of the outage probability of a two-source block-fading single-antenna Gaussian interference channel in the high-SNR regime by means of the diversity-multiplexing tradeoff. A general setting where the user rates and the average channel gains are not restricted to be symmetric is investigated. This asymmetric scenario allows to analyze networks with “mixed” interference, i.e., when different sources are at different distance from their intended destination, that are not possible under the commonly used symmetric assumption. Inner and outer bounds for the diversity are derived. The outer bound is based on the recent “to within one bit” capacity result of Etkin for the unfaded Gaussian channel and is a re-derivation of a known bound for which an error is pointed out. The inner bound is based on the Han and Kobayashi achievable region both without rate splitting and with a rate spitting inspired by the “to within one bit” capacity result. An analytical comparison of the diversity upper and lower bounds for a general channel seems difficult; by numerical evaluations, the two bounds are shown to coincide for a fairly large set of channel parameters.
Magnet power supplies for the Advanced Light Source

The Lawrence Berkeley Laboratory (LBL) is building an Advanced Light Source (ALS) to produce synchrotron radiation. An electron linear accelerator and a booster synchrotron are used to accelerate the electron beam to 1.5 GeV to fill the storage ring. The power supplies used for the magnets in the booster and the storage ring are described, as are the interface requirements for computer control and monitoring of the power supplies and magnet currents. >
Full Three Dimensional Orbits for Multiple Stars on Close Approaches to the Central Supermassive Black Hole

PACS 04A25 With the advent of adaptive optics on the W. M. Keck 10m telescope, two significant steps forward have been taken in building the case for a supermassive black hole at the center of the Milky Way and understanding the black hole’s effect on its environment. Using adaptive o ptics and speckle imaging to study the motions of stars in the plane of sky with ±�2 mas precision over the past 7 years, we have obtained the firs t simultaneous orbital solution for multiple stars. Among the included stars, three are newly identified (S016, S0-19, S0-20). The most dramatic orbit is that of the newly identified star S0-16, which passed a mere 60 AU from the central dark mass at a velocity of 9,000 km/s in 1999. The orbital analysis results in a new central dark mass estimate of 3.6(±0.4) × 10 6 (( R o 8kpc ) 3 M ⊙. This dramatically strengthens the case for a black hole at the center of our Galaxy, by confining the dark ma tter to within a radius of 0.0003 pc or 1,000 Rsh and thereby increasing the inferred dark mass density by four orders of magnitude compared to earlier estimates. With the introduction of an adaptive-optics-fed spectrometer, we have obtained the first detection of spectral absorption lines in one of the high-velocity stars , S0-2, one month after its closest approach to the Galaxy’s central supermassive black hole. Both Br (2.1661 µm) and He I (2.1126 µm) are seen in absorption with equivalent widths and an inferred stellar r otational velocity that are consistent with that of an O8-B0 dwarf, which suggests that S0-2 is a massive (�15 M⊙), young (<10 Myr) main sequence star. Similarly, the lack of CO detected in our first AO spectra sugg est that several other of the high-velocity stars are also young. This presents a major challenge to star formation theories, given the strong tidal forces that prevail over all distances reached by these stars in the ir current orbits and the difficulty in migrating these stars inward during their lifetime from further out where tidal forces should no longer preclude star formation.
Rational Inattention and Energy Efficiency

AbstractThis paper argues that it will often be rational for consumers to pay limited attention to energy efficiency when choosing among energy-consuming durable goods like automobiles or home appliances. The reason is that the proper valuation of energy efficiency requires time and effort, but differences in efficiency across products will rarely be pivotal to choice when consumers have strong preferences regarding other product attributes. The paper first explains why proper valuation of efficiency is difficult, even in the presence of government energy labels. It next develops a model that shows how to value additional information about energy efficiency in a discrete-choice context. It then uses data on automobiles to show that consumers experience only small welfare losses when forced to choose a car without detailed information about fuel costs. Finally, the paper discusses the implications of rational inattention for both economic research and public policy.
D-Minus Elections: The Politics and Norms of International Election Observation

As international election monitors have grown active worldwide, their announcements have gained influence. Sometimes, however, they endorse highly flawed elections. Because their leverage rests largely on their credibility, this is puzzling. Understanding the behavior of election monitors is important because they help the international community to evaluate the legitimacy of governments and because their assessments inform the data used by scholars to study democracy. Furthermore, election monitors are also particularly instructive to study because the variety of both intergovernmental and nongovernmental organizations that observe elections makes it possible to compare them across many countries and political contexts. This study uses a new dataset of 591 international election-monitoring missions. It shows that despite their official mandate to focus on election norms, monitors do not only consider the elections' quality; their assessments also reflect the interests of their member states or donors as well as other tangential organizational norms. Thus, even when accounting as best as possible for the nature and level of irregularities in an election, monitors' concerns about democracy promotion, violent instability, and organizational politics and preferences are associated with election endorsement. The study also reveals differences in the behavior of intergovernmental and nongovernmental organizations and explains why neither can pursue their core objectives single-mindedly.
A Parallel Implementation of a Computational Aeroacoustic Algorithm for Airfoil Noise

The long-term objective of the research described in this paper is to use CAA methodology and parallel computers to increase the understanding of broadband blade noise. In a systematic progression towards simulations of completely realistic configurations and conditions, some simplified problems that address the important features of the flow are investigated. A two-dimensional, Euler code, implemented using the message passing library and Fortran 90 on the IBM SP2, is used to perform the calculations. Results are presented for the interaction of a vortical gust and a flat plate.
Distributed spanner construction in doubling metric spaces

This paper presents a distributed algorithm that runs on an n-node unit ball graph (UBG) G residing in a metric space of constant doubling dimension, and constructs, for any e 0, a (1 + e)-spanner H of G with maximum degree bounded above by a constant. In addition, we show that H is “lightweight”, in the following sense. Let Δ denote the aspect ratio of G, that is, the ratio of the length of a longest edge in G to the length of a shortest edge in G. The total weight of H is bounded above by O(logΔ) · wt(MST), where MST denotes a minimum spanning tree of the metric space. Finally, we show that H satisfies the so called leapfrog property, an immediate implication being that, for the special case of Euclidean metric spaces with fixed dimension, the weight of H is bounded above by O(wt(MST)). Thus, the current result subsumes the results of the authors in PODC 2006 that apply to Euclidean metric spaces, and extends these results to metric spaces with constant doubling dimension.
The primary pediatrician's role when a death occurs in a family in one's practice.

1. Morris A. Wessel, MD 1. Clinical Professor of Pediatrics, Yale University School of Medicine, New Haven, Connecticut Losses due to death may seem to be infrequent for children cared for by primary pediatricians because fatal illnesses occur less frequently than in former years. However, some mothers miscarry or give birth to preterm infants who fail to survive. Grandparents often die. And more often than we realize, a parent dies. During the first 10 years of their lives, 6% of children lose a parent. Children often experience other vital losses, such as uncles, aunts, cousins, siblings, playmates, teachers, and favorite recreation leaders. The highly televised deaths of individuals who children never may have met, such as Martin Luther King, Jr, President John F. Kennedy, and those killed during the September 11 terrorist attack, evoke frightening feelings among children as well as adults. Forty years ago, early in my years of pediatric practice, I was surprised to observe during pediatric prenatal conferences that women and men frequently became tearful when discussing family medical histories and deaths of loved ones that took place during their childhood. One woman recalled: “I was 4 years old when my grandmother died. I was sent to a friend’s house for the day. When I returned home in the evening, my grandmother was gone. I was very upset. It was several years before I understood what had happened to her.” Although my own father died when I was an infant, a loss that permeated my childhood and adolescence, I was slow to realize the importance of the role that I as a primary pediatrician could assume when children and adolescents in my practice experienced the death of relatives or close friends. Grieving following the loss of an important person in one’s life is not an illness that can be cured. It is, however, a major stressful experience for children and their parents. The American Academy …
Increasing the output of a Littman-type laser by use of an intracavity Faraday rotator

We present a method of external-cavity diode-laser grating stabilization that combines the high output power of the Littrow design with the fixed output pointing of the Littman-Metcalf design. Our new approach utilizes a Faraday-effect optical isolator inside the external cavity. Experimental testing and a model that describes the tuning range and optimal tuning parameters of the laser are described. Preliminary testing of this design has resulted in a short-term linewidth of 360 kHz and a side-mode suppression of 37 dB. The laser tunes mode hop free over 7 GHz, and we predict that much larger tuning ranges are possible.
The impact and enforcement of prudent layperson laws.

Abstract Study objective Almost every state has enacted a "prudent layperson" standard for determining insurance coverage for emergency department (ED) services. This study evaluates whether these laws are achieving their goals or causing unintended side effects. Methods Six states were selected for in-depth case studies to represent a range of market, demographic, and legal conditions. In each state, 11 to 15 interviews were conducted with insurers, regulators, providers, employers, patient advocates, and industry observers, for a total of 87 interviews. In addition, regulators in all 50 states completed a written survey about likely enforcement responses for hypothetical violations of these laws. Results Basic compliance with prudent layperson laws appears to be widespread. Regulators actively enforce these laws, and most subjects reported no systematic violations. Insurers explained that it is difficult to operationalize a coverage standard that relies on patients' experience of symptoms rather than on providers' assignment of diagnostic and procedure codes. No strong evidence was found that these laws have significantly increased insurance costs, which is due in part to various strategies insurers have adopted to reduce payments to providers for ED services and to greatly increase patients' copayments. Accordingly, few subjects believe these laws have increased inappropriate ED use. Conclusion Prudent layperson laws have helped to catalyze industry-wide changes in how health insurers review ED claims and how they manage ED costs. Whether these changes, on balance, are beneficial to patients and to society requires further study focused on outcomes and system-wide costs.