cssi/SciSciGPT-SciSciNet huggingface dataset:
Extreme point results for robust stability of interval plants: beyond first order compensators

Motivated by robust stabilization of interval plants, this paper concentrates on a fundamental problem involving a family of polynomials obtained via convex combination of “extreme members”. The objective is to provide conditions under which stability of the extremes implies stability of the entire family. Although the existing literature contains rather strong extreme point results involving frequency domain analysis, there is a paucity of more direct coefficient space criteria—this paper deals exclusively with the coefficient space problem. To this end, we introduce the so-called Alternating Hurwitz Minor Condition (AHMC) and show how it can be used to enlarge the class of polynomial families for which extreme point results can be obtained. Subsequently, the ramifications on robust stability of interval plants are fully explained. In contrast to existing literature for first order compensators, the AHMC makes it possible to deal with classes of higher order compensators in an extreme point context.
Purchasing Power Parity Exchange Rates for the Global Poor

The first of the Millennium Development Goals targets global poverty. The global poverty number is estimated by the World Bank as a worldwide count of people who live below a common international poverty line. This line, loosely referred to as the dollar-a-day line, is calculated as an average over the world’s poorest countries of their national poverty lines expressed in international dollars. The average is then converted back to local currency to calculate each country’s counts of those living below the line. The counts come from household surveys, the number and coverage of which have steadily increased over the years. The conversion of national poverty lines to international currency and the conversion of the global line back to local currency are both done using purchasing power parity (PPP) exchange rates from the various rounds of the International Comparison Program (ICP). These PPPs, unlike market exchange rates, are constructed as multilateral price indexes using directly observed consumer prices in many countries. This paper is about the construction of the PPPs and their effect on the poverty estimates. In the first dollar-a-day poverty calculations, the World Bank (1990) used price indexes for GDP, but this practice was later improved by the use of price indexes for household consumption. Yet even this may be misleading if the price indexes for national aggregate consumption are different from those relevant for people who live at or around the global poverty line. Price indexes are weighted averages
FREEDMAN'S INEQUALITY FOR MATRIX MARTINGALES

Freedman's inequality is a martingale counterpart to Bernstein's inequality. This result shows that the large-deviation behavior of a martingale is controlled by the predictable quadratic variation and a uniform upper bound for the martingale difference sequence. Oliveira has recently established a natural extension of Freedman's inequality that provides tail bounds for the maximum singular value of a matrix-valued martingale. This note describes a different proof of the matrix Freedman inequality that depends on a deep theorem of Lieb from matrix analysis. This argument delivers sharp constants in the matrix Freedman inequality, and it also yields tail bounds for other types of matrix martingales. The new techniques are adapted from recent work by the present author.
Ubicomp's colonial impulse

Ubiquitous computing has a grand vision. Even the name of the area identifies its universalizing scope. In this, it follows in a long tradition of projects that attempt to create new models and paradigms that unite disparate, distributed elements into a large conceptual whole. We link concerns in ubiquitous computing into a colonial intellectual tradition and identify the problems that arise in consequence, explore the locatedness of innovation, and discuss strategies for decolonizing ubicomp's research methodology.
Recent Applications of Fluorous Separation Methods in Organic and Bioorganic Chemistry

Initially introduced as a niche technique to recover and recycle catalysts, fluorous chemistry has rapidly expanded into organic synthesis and combinatorial chemistry over the past 12 years. Recently, fluorous methods are also enabling purification of biomolecules such as peptides, oligosaccharides, and oligonucleotides assembled by traditional solid-phase synthesis. Apart from synthetic applications, fluorous chemistry is also providing solutions for critical problems in proteomics and microarray chip technology. This review highlights selected recent advances that underscore the impact of fluorous separation methods in organic and bioorganic chemistry.
An Improved Measure of Quasar Orientation

Radio core dominance, usually measured by R, the rest frame ratio of core to lobe flux density, has been used as an indicator of Doppler boosting of a quasar's radio jets and hence the inclination of the central engine's spin axis to the line of sight. The use of lobe flux density as a means of normalizing the boosted core flux density to the available intrinsic power of the central engine introduces scatter. This is because the emission from the radio lobes depends strongly on the interaction of the jet with the environment at distances beyond several kiloparsecs from the nucleus. Total kinetic power in the extended radio emission is approximately proportional to emission-line luminosity, and emission-line luminosity is proportional to the luminosity of the featureless continua of active galactic nuclei?both over four orders of magnitude. Thus, a quasar's optical luminosity may be an excellent measure of available intrinsic jet power. Therefore, we define a new core dominance parameter, RV, the ratio of radio core to optical (rest frame V band) continuum luminosity, that is not directly dependent on jet interactions with the super-kiloparsec-scale environment. We show that the use of RV, rather than R, results in significantly improved inverse correlations with the beaming angle as deduced from apparent superluminal velocities and inverse-Compton-scattered X-ray emission and with the FWHM of a quasar's broad H? emission line. We discuss some implications and applications of the new parameter.
The Effect of Family Planning Programs on the Fertility of Welfare Recipients Evidence from Medicaid Claims

This paper explores the effectiveness of family planning (FP) services subsidized by the Medicaid program in lowering the fertility of female welfare recipients. Previous studies used single-equation estimates and produced conflicting and sometimes confounding results. Thus this study employed a bivariate probit model to estimate the effect of contraceptive acceptance on the individuals probability of giving birth without the bias that may result from single-equation estimates. A unique data set created from Maryland Medicaid claims records was also used. Results suggest that Medicaid FP programs are much more effective at lowering fertility than indicated by previous studies using single-equation estimates.
Design, Simulation, and Testing of an EHV Metal-Enclosed Disconnector

One of the most demanding design issues in the development of metal-clad disconnectors for applications at 500 kV and over is to ensure the switching capabilities of the device. This paper presents the issues and processes involved from the initial design through to final testing of a 550 kV disconnector. The initial work concentrated on defining the design parameters in order to minimize the risk of arc breakout. Computer analysis using 2D and 3D modeling of the contact configuration was carried out. As a following step, before building the disconnector the results of the computations were validated by a static test where the electrode arrangement was set manually at different gap distances and discharges between contacts were monitored. From the computational and test data a final contact design was optimized and a disconnector prototype was built. Finally, the capabilities for bus-charging current switching were tested in accordance with the IEC 1259 standard. The results of these tests include measurement and comparison with EMTP simulations of the fast transient over voltages generated by disconnector operations.
The baryon-dark matter ratio via moduli decay after Affleck-Dine baryogenesis

Low-scale supersymmetry breaking in string motivated theories implies the pres- ence of O(100TeV) scale moduli, which generically lead to a significant modification of the history of the universe prior to Big Bang Nucleosynthesis. Such an approach implies a non- thermal origin for dark matter resulting from scalar decay, where the lightest supersymmetric particle can account for the observed dark matter relic density. We study the further effect of the decay on the baryon asymmetry of the universe, and find that this can satisfactorily address the problem of the over-production of the baryon asymmetry by the Affleck-Dine mechanism in the MSSM. Remarkably, there is a natural connection between the baryon and dark matter abundances today, which leads to a solution of the 'Cosmic Coincidence Problem'.
Unsteady airloads in supercritical transonic flows

Results obtained from a simplified theory of unsteady perturbations of supercritical two-dimensional transonic flows, introduced in an earlier paper, are presented. Unsteady loads generated by an oscillating flap and by airfoils oscillating as a whole are given with comparisons to experimental results and finite difference solutions. The theory, which was originally formulated for symmetric airfoils at zero mean angle of attack, is extended to treat asymmetric mean flows.
Resonances and superlattice pattern stabilization in two-frequency forced Faraday waves

We investigate the role weakly damped modes play in the selection of Faraday wave patterns forced with rationally related frequency components mω and nω. We use symmetry considerations to argue for the special importance of the weakly damped modes oscillating with twice the frequency of the critical mode, and those oscillating primarily with the “difference frequency” |n − m|ω and the “sum frequency” (n + m)ω. We then perform a weakly nonlinear analysis using equations of Zhang and Vinals [J. Fluid Mech. 336 (1997) 301] which apply to small-amplitude waves on weakly inviscid, deep fluid layers. For weak damping and forcing and one-dimensional waves, we perform a perturbation expansion through fourth-order which yields analytical expressions for onset parameters and the cubic bifurcation coefficient that determines wave amplitude as a function of forcing. For stronger damping and forcing we numerically compute these same parameters, as well as the cubic cross-coupling coefficient for competing standing waves oriented at an angle θ relative to each other. The resonance effects predicted by symmetry are borne out in the perturbation results for one spatial dimension, and agree with the numerical results for two dimensions. The difference frequency resonance plays a key role in stabilizing superlattice patterns of the SL-I type
Effects of scheduling on file memory operations

File system activity is a prime factor affecting the throughput of any computing system, for the file memory is, in a very real sense, the heart of the system. No program can ever be executed without such secondary storage. It is here that input files are stored, that files resulting as the output of processes are written, that "scratchwork" required by operating processes may be placed. In a multiprogrammed computing system, there is a considerable burden on secondary storage, resulting both from constant traffic in and out of main memory (core memory), and from the large number of permanent files that may be in residence. It is clear that the demand placed on the file memory system is extraordinarily heavy; and it is essential that every part of the computing system interacting with file memory do so smoothly and efficiently.
Analytic correction for scatter in fully 3D PET: statistical issues

Scatter correction methods based on the analytical calculation of the scatter distribution can only estimate scatter from regions outside the field-of-view if transmission and emission scans of these regions exist. The duration of such scans must be short if they are to be acquired in a clinical setting. The effect of scan duration on the accuracy of the scatter estimates is investigated here. It is shown that the correction is insensitive to poor counting statistics in the emission scan, but is strongly affected by poor counting statistics in the transmission scan. Applying an adaptive segmentation algorithm to the transmission data greatly improves performance. Satisfactory scatter estimates are possible with transmission scans as short as one minute.
How Bad are Central Asia’s Business Environments and What Can be Done about Them?

Central Asian countries need private investment to promote growth and to meet economic diversifi cation goals. This article starts by looking at what we know about determinants of external and domestic investment, the key driver of private sector growth. Country context matters greatly when judging the importance of business environments in determining investment. Countries that have attracted substantial private investment and the growth that comes with it that exhibited middling to poor business environments all share certain characteristics. They are large in population terms, geographically well located, and none is landlocked. Small countries, and countries less well situated geographically that did well in attracting investment and achieving high growth were all at or near the top of business environment rankings. If Central Asia’s relatively
Asymmetric catalysis with "planar-chiral" derivatives of 4-(dimethylamino)pyridine.

Whereas chiral Lewis acid catalysis has been intensively investigated, chiral Lewis base (nucleophilic) catalysis has been comparatively neglected. We have developed “planar-chiral” derivatives of 4-(dimethylamino)pyridine (DMAP), a highly versatile nucleophilic catalyst, that are effective in a diverse array of processes, including the Staudinger synthesis of β-lactams, the acylation of silyl ketene acetals, and the kinetic resolution of amines.
Detecting Primary User Emulation Attacks in Cognitive Radio Networks via Physical Layer Network Coding

Primary user emulation (PUE) attacks on cognitive radio networks pose a serious threat to the deployment of this technique. Previous approaches usually depend on individual or combined received signal strength (RSS) measurements to detect emulators. In this paper, we propose a new mechanism based on physical layer network coding to detect the emulators. When two signal sequences interfere at the receiver, the starting point of collision is determined by the distances among the receiver and the senders. Using the signal interference results at multiple receivers and the positions of reference senders, we can determine the position of the ‘claimed’ primary user. We can then compare this localization result with the known position of the primary user to detect the PUE attack. We design a PUE detection mechanism for wireless networks with trustworthy reference senders. We analyze the overhead of the proposed approach and study its detection accuracy through simulation. c � 2013 Published by Elsevier Ltd. Selection and/or peer-review under responsibility of Z. Khan and N. Javaid.
Equitable and adversarial pricing for items under warranty

Most manufactured goods entail the involvement of three parties, a manufacturer, an intermediary and a customer. Usually, the manufacturer warranties his/her product against defects to the intermediary, who in turn extends this warranty to the customer. Here, we consider the manufacturer’s warranty to the intermediary providing the free replenishment of failed items within a specific period. Specifically, we focus on the matter of how manufacturer and intermediary arrive upon a unit price per item that the manufacturer can levy against the intermediary. First, we discuss two equitable scenarios; one in which both manufacturer and intermediary strive for fairness with a common probability distribution about the number of unit failures within a prescribed warranty period, and the other wherein manufacturer and intermediary have different distributions, but they arrive upon a consensus by a process of co-operation. Then, we discuss the adversarial scenario wherein each strives to maximize his/her expected utility without knowledge of the other’s utilities and without using a common distribution. This latter scenario is perhaps the more realistic one, in the sense of what is done in practice. However, a discussion of the equitable scenario may be useful in matters of litigation pertaining to warranty claims and violations.
Mahler Measure of Alexander Polynomials

Let l be an oriented link of d components in a homology 3-sphere. For any nonnegative integer q, let l(q) be the link of d-1 components obtained from l by performing 1/q surgery on the dth component. Then the Mahler measure of the Alexander polynomial of l(q) converges to the Mahler measure of the Alexander polynomial of l as q goes to infinity, provided that some other component of l has nonzero linking number with the dth. Otherwise, the Mahler measure of the Alexander polynomial of l(q) has a well-defined bu different limiting behavior. Examples are given of links for which the Mahler measure of the Alexander polynomial is small. Possible connection with hyperbolic volume are discussed.
Secure Communication in the Low-SNR Regime

Secrecy capacity of a multiple-antenna wiretap channel is studied in the low signal-to-noise ratio (SNR) regime. Expressions for the first and second derivatives of the secrecy capacity with respect to SNR at SNR = 0 are derived. Transmission strategies required to achieve these derivatives are identified. In particular, it is shown that it is optimal in the low-SNR regime to transmit in the maximal-eigenvalue eigenspace of φ = Hm† Hm - Nm/Ne He†He where Hm and He denote the channel matrices associated with the legitimate receiver and eavesdropper, respectively, and Nm and Ne are the noise variances at the receiver and eavesdropper, respectively. Energy efficiency is analyzed by finding the minimum bit energy required for secure and reliable communications, and the wideband slope. Increased bit energy requirements under secrecy constraints are quantified. Finally, the impact of fading is investigated, and the benefits of fading in terms of energy efficiency are shown.
Ground-Wave Propagation over Arctic Sea Ice

Radio ground-wave propagation in the Arctic Ocean occurs over mixed paths. The mixed paths include layered or homogeneous sea ice and sea water. Amplitude and phase variations occurring as "dropoff" or "recovery" effects at the ice-sea-water boundaries provide a technique for sea-ice mapping and an explanation for anomalous radio reception. The phase variations are more sensitive over short distances from the mixed path boundaries. Center for Research in Engineering Science
The ‘‘Glass of Milk’’ Subsidy Program and Malnutrition in Peru

This study of the Vaso de Leche ('glass of milk') feeding program in Peru looks for evidence that this in-kind transfer program aimed at young children furthers nutritional objectives. The study links public expenditure data with household survey data to substantiate the targeting and to model the determinants of nutritional outcomes. It confirms that the social transfer program targets poor households and households with low nutritional status. Nevertheless, the study fails to find econometric evidence that the nutritional objectives are being achieved.
Encoding methods for combinatorial chemistry

Assuming that the chemical reactions used to synthesize a combinatorial library member are successful, then knowledge of the specific reaction sequence is equivalent to knowing the member's chemical identity. Because the determination of chemical identity is typically not automatable and requires a substantial amount of material, schemes that encode a member's reaction history onto the reaction platform are of value. The primary benefits of encoding are relational nomenclature (all methods) and automated handling (some methods). Encoding methods evaluated to date are spatial, graphical, chemical, spectrometric, electronic, and physical.
Triangles and Groups via Cevians

For a given triangle T and a real number ρ we define Ceva’s triangle \({\mathcal{C}_{\rho}(T)}\) to be the triangle formed by three cevians each joining a vertex of T to the point which divides the opposite side in the ratio ρ: (1 – ρ). We identify the smallest interval \({\mathbb{M}_T \subset \mathbb{R}}\) such that the family \({\mathcal{C}_{\rho}(T), \rho \in \mathbb{M}_T}\), contains all Ceva’s triangles up to similarity. We prove that the composition of operators \({\mathcal{C}_\rho, \rho \in \mathbb{R}}\), acting on triangles is governed by a certain group structure on \({\mathbb{R}}\). We use this structure to prove that two triangles have the same Brocard angle if and only if a congruent copy of one of them can be recovered by sufficiently many iterations of two operators \({\mathcal{C}_\rho}\) and \({\mathcal{C}_\xi}\) acting on the other triangle.
EXPLAINING THE “IDENTIFIABLE VICTIM EFFECT”

It is widely believed that people are willing to expend greater resources to save the lives of identified victims than to save equal numbers of unidentified or statistical victims. There are many possible causes of this disparity which have not been enumerated previously or tested empirically. We discuss four possible causes of the “identifiable victim effect” and present the results of two studies which indicate that the most important cause of the disparity in treatment of identifiable and statistical lives is that, for identifiable victims, a high proportion of those at risk can be saved.
Reconfigurability and reliability of systolic/wavefront arrays

The authors study fault-tolerant redundant structures for maintaining reliable arrays. In particular, they assume that the desired array (application graph) is embedded in a certain class of regular, bounded-degree graphs called dynamic graphs. The degree of reconfigurability (DR) and DR with distance (DR/sup d/) of a redundant graph are defined. When DR and DR/sup d/ are independent of the size of the application graph, the graph is finitely reconfigurable (FR) and locally reconfigurable (LR), respectively. It is shown that DR provides a natural lower bound on the time complexity of any distributed reconfiguration algorithm and that there is no difference between being FR and LR on dynamic graphs. It is also shown that if both local reconfigurability and a fixed level of reliability are to be maintained, a dynamic graph must be of a dimension at least one greater than the application graph. Thus, for example, a one-dimensional systolic array cannot be embedded in a one-dimensional dynamic graph without sacrificing either reliability or locality of reconfiguration. >
An improved synthesis of pyrroles from N-p-toluenesulfonylglycine esters and α,β-unsaturated aldehydes and ketones

N-p-Toluenesulfonylglycine esters 2 condensed with α,β-unsaturated carbonyl compounds 1 in the presence of the non-nucleophilic base DBU to give hydroxypyrrolidines 3. Dehydration with phosphorus oxychloride-pyridine, followed by DBU mediated elimination of p-toluenesulfinic acid, gave a series of synthetically useful pyrrole-2-carboxylates 5.
A synthetic approach toward the proposed tetracyclic aziridinomitosene derived from FK317.

A synthesis of the FK317 derivative 25 is described using internal Michael addition. Tin−lithium exchange of the deuterated stannylaziridine 18 generated the key lithioaziridine intermediate, followed by cyclization and aromatization of the pyrrole ring to give 7. Ester reduction from 7 to 23 was effected via temporary aldehyde protection as the silylimidazole adduct 22, and conversion to the carbamate 25 was carried out using FmocNCO and FMOC cleavage. Structure 25 is the N-trityl-protected derivative of the proposed intermediate from bioactivation of FK317 that is responsible for DNA cross-linking. Attempted nitrogen deprotection of 25 using MsOH/i-Pr3SiH resulted in replacement of the C(10) carbamate by hydride. Deprotection of the more stable 21 gave the desired aziridine 26.
The Dynamics of Agricultural Biotechnology Adoption: Lessons from series rBST Use in Wisconsin, 1994–2001

This article exploits panel data from Wisconsin dairy farmers to examine the dynamics of recombinant bovine somatotropin (rBST) adoption and to identify the characteristics that distinguish among nonadopters, disadopters, and early and late adopters. Panel methods are used to control for omitted variables and endogenous regressors that call into question coefficient estimates derived from cross-section adoption models. The results, however, confirm previous findings that larger farms with complementary feeding technologies are more likely to adopt rBST, nonadopters appear quite unlikely to become adopters, and rBST adoption will remain at rather moderate levels in Wisconsin.
Tailoring wind properties by various passive roughness elements in a boundary-layer wind tunnel

Boundary-layer wind tunnel provides a unique platform to reproduce urban, suburban and rural atmospheric boundary layer (ABL) by using roughness devices such as vortex generators, floor roughness, barrier walls, and slots in the extended test-section floor in the contraction cone. Each passive device impacts wind properties in a certain way. In this study, influence of various passive devices on wind properties has been investigated. Experiments using eighteen different configurations of the passive devices have been carried out to simulate urban, sub-urban, and rural climate conditions in a boundary-layer wind tunnel. The effect of each configuration on the wind characteristics is presented. It was found that higher barrier height and more number of roughness elements on the floor, generated higher turbulence and therefore higher model scale factors were obtained. However, increased slot width in the extended test-section floor in the contraction cone of the wind tunnel seemed to have a little effect on wind characteristics.
Orthogonal to the Java Imperative

Three nontrivial limitations of the existing Javaℳ technology are considered from the viewpoint of object-oriented database technology. The limitations are: lack of support for orthogonal persistence, lack of parametric (and in fact bounded and F-bounded) polymorphism and lack of an assertion (constraint) language. These limitations are overcome by leaving Java as it is, and developing a declarative (query in particular) component of the Java technology. This declarative language is implemented on top of the Java Virtual Machine, extended with orthogonal and transitive persistence. The model of persistence also features complex name space management.
Questions of identity

As an introduction to {nu}Fact '99, the ICFA/ECFA Workshop on Neutrino Factories Based on Muon Storage Rings, I place the issues of neutrino properties and neutrino oscillations in the broader context of fermion flavor.
Semiconductor Nanowires for Artificial Photosynthesis

In this Perspective, we discuss current challenges in artificial photosynthesis research, with a focus on the benefits of a nanowire morphology. Matching the flux between electrocatalysts and light-absorbers, and between individual semiconducting light-absorbers, are two major issues to design economically viable devices for artificial photosynthesis. With the knowledge that natural photosynthesis is an integrated nanosystem, individual building blocks of biomimetic artificial photosynthesis are discussed. Possible research directions are presented under an integrated device design scheme, with examples of our current progress in these areas. Coupling all of the components together, including electrocatalysts, light- absorbers, and charge transport units, is crucial due to both fundamental and practical considerations. Given the advantages of one-dimensional nanostructures, it is evident that semiconductor nanowires can function as essential building blocks and help to solve many of the issues in artificial photosynthesis.
The effect of marginal tax rates on income: a panel study of 'bracket creep'

This paper uses a panel of individual tax returns and the 'bracket creep' as source of tax rate variation to construct instrumental variables estimates of the sensitivity of income to changes in tax rates. From 1979 to 1981, the US income tax schedule was fixed in nominal terms while inflation was high (around 10%). This produced a real change in tax rate schedules. Taxpayers near the top-end of a tax bracket were more likely to creep to a higher bracket and thus experience a rise in marginal rates the following year than the other taxpayers. Compensated elasticities can be estimated by comparing the differences in changes in income between taxpayers close to the top-end of a tax bracket to the other taxpayers. These estimates, based on comparisons between very similar groups, are robust to underlying changes in the income distribution, such as a rise in inequality. The elasticities of taxable income and adjusted gross income are around 0.4 and significant but the elasticities of wage income are in general insignificant and close to zero.  2002 Elsevier Science B.V. All rights reserved.
Smeared phase transition in a three-dimensional Ising model with planar defects: Monte Carlo simulations

We present results of large-scale Monte Carlo simulations for a three-dimensional Ising model with short-range interactions and planar defects, i.e., disorder perfectly correlated in two dimensions. We show that the phase transition in this system is smeared, i.e., there is no single critical temperature, but different parts of the system order at different temperatures. This is caused by effects similar to but stronger than Griffiths phenomena. In an infinite-size sample there is an exponentially small but finite probability to find an arbitrary large region devoid of impurities. Such a rare region can develop true long-range order while the bulk system is still in the disordered phase. We compute the thermodynamic magnetization and its finite-size effects, the local magnetization, and the probability distribution of the ordering temperatures for different samples. Our Monte-Carlo results are in good agreement with a recent theory based on extremal statistics.
Asymptotics of Weil-Petersson geodesics II: bounded geometry and unbounded entropy

We use ending laminations for Weil–Petersson geodesics to establish that bounded geometry is equivalent to bounded combinatorics for Weil–Petersson geodesic segments, rays, and lines. Further, a more general notion of non-annular bounded combinatorics, which allows arbitrarily large Dehn-twisting, corresponds to an equivalent condition for Weil–Petersson geodesics. As an application, we show theWeil–Petersson geodesic flow has compact invariant subsets with arbitrarily large topological entropy.
ESTIMATING MARGINAL RETURNS TO MEDICAL CARE: EVIDENCE FROM AT-RISK NEWBORNS

A key policy question is whether the benefits of additional medical expenditures exceed their costs. We propose a new approach for estimating marginal returns to medical spending based on variation in medical inputs generated by diagnostic thresholds. Specifically, we combine regression discontinuity estimates that compare health outcomes and medical treatment provision for newborns on either side of the very low birth weight threshold at 1500 grams. First, using data on the census of US births in available years from 1983-2002, we find that newborns with birth weights just below 1500 grams have lower one-year mortality rates than do newborns with birth weights just above this cutoff, even though mortality risk tends to decrease with birth weight. One-year mortality falls by approximately one percentage point as birth weight crosses 1500 grams from above, which is large relative to mean infant mortality of 5.5% just above 1500 grams. Second, using hospital discharge records for births in five states in available years from 1991-2006, we find that newborns with birth weights just below 1500 grams have discontinuously higher charges and frequencies of specific medical inputs. Hospital costs increase by approximately $4,000 as birth weight crosses 1500 grams from above, relative to mean hospital costs of $40,000 just above 1500 grams. Under an assumption that observed medical spending fully captures the impact of the "very low birth weight" designation on mortality, our estimates suggest that the cost of saving a statistical life of a newborn with birth weight near 1500 grams is on the order of $550,000 in 2006 dollars.
First order decision diagrams for relational MDPs

Markov decision processes capture sequential decision making under uncertainty, where an agent must choose actions so as to optimize long term reward. The paper studies efficient reasoning mechanisms for Relational Markov Decision Processes (RMDP) where world states have an internal relational structure that can be naturally described in terms of objects and relations among them. Two contributions are presented. First, the paper develops First Order Decision Diagrams (FODD), a new compact representation for functions over relational structures, together with a set of operators to combine FODDs, and novel reduction techniques to keep the representation small. Second, the paper shows how FODDs can be used to develop solutions for RMDPs, where reasoning is performed at the abstract level and the resulting optimal policy is independent of domain size (number of objects) or instantiation. In particular, a variant of the value iteration algorithm is developed by using special operations over FODDs, and the algorithm is shown to converge to the optimal policy.
A Fast Algorithm for Computing Geodesic Distances in Tree Space

Comparing and computing distances between phylogenetic trees are important biological problems, especially for models where edge lengths play an important role. The geodesic distance measure between two phylogenetic trees with edge lengths is the length of the shortest path between them in the continuous tree space introduced by Billera, Holmes, and Vogtmann. This tree space provides a powerful tool for studying and comparing phylogenetic trees, both in exhibiting a natural distance measure and in providing a euclidean-like structure for solving optimization problems on trees. An important open problem is to find a polynomial time algorithm for finding geodesics in tree space. This paper gives such an algorithm, which starts with a simple initial path and moves through a series of successively shorter paths until the geodesic is attained.
Mill’s extraordinary utilitarian moral theory

D.G. Brown’s revisionist interpretation, despite its interest, misrepresents Mill’s moral theory as outlined in Utilitarianism . Mill’s utilitarianism is extraordinary because it explicitly aims to...
Efficient Laser Anemometer for Intra-Rotor Flow Mapping in Turbomachinery

A fringe type laser anemometer is described. Features of the anemometer include; a rapid and efficient data acquisition process; a detailed real time graphic display of the data being accumulated; and input laser beam positioning that maximizes the size of the intrarotor region being mapped. Results are presented that demonstrate the anemometer's capability in flow mapping within a transonic axial flow compressor rotor. A velocity profile, derived from 30,000 measurements along 1000 sequential circumferential positions covering 20 blade passages, was obtained in 30 seconds. The use of fluorescent seed particles allowed flow measurements near the rotor hub and the casing window.
Calculating transmission line inductance using interval mathematics

Uncertainty is a major issue facing electric utilities in planning and decision making. Modeling uncertainty can be based on two general approaches. The first is a probabilistic approach where probability distributions for all of the uncertainties are assumed. The second approach is called "Unknown but Bounded" in which upper and lower limits on the uncertainties are assumed without probability distributions. Interval mathematics provides a tool for the practical implementation and extension of the unknown but bounded concept. The calculation of transmission line inductance is used as an example to illustrate the use of interval mathematics. Inductance values are calculated using the traditional single point numbers as well as interval numbers. The values from these two methods are compared to prove the validity of interval analysis
Litigation as public health policy: theory or reality?

In the past decade, public health advocates have used litigation to achieve public policy goals that have not been attainable through the political process. An important question to consider is whether the litigation brought so far has actually influenced the policy agenda. The authors conclude that the evidence from recent tobacco and gun litigation presents a decidedly mixed picture of the efficacy of litigation as a public health policy strategy.
THE TURVILLE INFINITY BINOCULAR BALANCE TEST

To summarise: The Turville method of subjective refraction was applied to 215 consecutive patients. The prescription determined by this method was given each patient regardless of the results of other tests and even against the writer's judgment in some cases. In slightly less than 10 per cent, of these subjects the prescription departed significantly from that which would have been given ordinarily. The prescription was changed in three out of these 21 cases at a subsequent date, two because of binocular difficulties arising from the incorporation of vertical prism and the third because some latent hypermetropia became manifest. A significant departure was assumed to be more than a 0.50 D. difference in the sphere, more than a 0.25 D. difference in the cylinder, 10d or more difference in the axis of the cylinder, and/or the incorporation of prism power in the prescription. After using the Turville method for over one year, the writer's enthusiasm for it, as an addition to routine refraction, is greater rather than less. Of course, it is not a sure-fire, fool-proof method of satisfying every patient. It is an important addition to routine refraction, perhaps as important as the flip cross cylinder. The writer no longer applies the results blindly as was done during the testing period, but be now modifies the prescription as indicated by the other tests and sometimes by intuition only based on previous experience.
Filters with active tuning for power applications

Filters for switched-mode power converters have traditionally relied on low-pass networks-with corner frequencies well below the ripple fundamental-to attenuate switching harmonics over a range of frequencies. The filters explored in this report provide extra attenuation at discrete frequencies, easing the filtering requirement of accompanying low-pass networks. When a converter's switching frequency is tuned to a filter resonance using a novel phase-lock control scheme, a resonant filter can match the ripple-attenuation performance of a low-pass network for less volume, weight, and expense. The design and application of resonant filters and active-tuning control are discussed, and experimental results from the input filter and power stage of a prototype DC-DC converter are presented.
A generalization of discrete hidden Markov model and of Viterbi algorithm

The concepts of composite and basic symbols and composite and basic states are introduced and a generalized hidden Markov model is defined to allow variable length and depth of dependency. A recursive function is defined to compute the probability distribution of the transitions from basic or composite states to composite states. The Viterbi algorithm is generalized to compute the optimal state sequence given an observation sequence of length T with time cost of O (T*(max.(N, N/sub c/))/sup 2/), where N and N/sub c/ are the numbers of basic states and composite states respectively. >
Synthesis of a novel triphosphate analogue: nucleoside α-P-borano, α-P-thiotriphosphate

The first boranothiotriphosphate compound, thymidine 5′-[α-P-borano, α-P-thio]triphosphate, in which borane and sulfur replace the two non-bridging oxygens of the α-phosphate in natural nucleoside triphosphates (NTPs), has been synthesized; some chemical properties of this borane–sulfur disubstituted nucleoside triphosphate analogue have been investigated. The synthetic approach reported here should be applicable for preparation of any α-borano, α-thio modified NTP or deoxy NTP; potential applications are discussed.
Cosmic rays and stochastic magnetic reconnection in the heliotail

Abstract. Galactic cosmic rays are believed to be generated by diffusive shock acceleration processes in Supernova Remnants, and the arrival direction is likely determined by the distribution of their sources throughout the Galaxy, in particular by the nearest and youngest ones. Transport to Earth through the interstellar medium is expected to affect the cosmic ray properties as well. However, the observed anisotropy of TeV cosmic rays and its energy dependence cannot be explained with diffusion models of particle propagation in the Galaxy. Within a distance of a few parsec, diffusion regime is not valid and particles with energy below about 100 TeV must be influenced by the heliosphere and its elongated tail. The observation of a highly significant localized excess region of cosmic rays from the apparent direction of the downstream interstellar flow at 1–10 TeV energies might provide the first experimental evidence that the heliotail can affect the transport of energetic particles. In particular, TeV cosmic rays propagating through the heliotail interact with the 100–300 AU wide magnetic field polarity domains generated by the 11 yr cycles. Since the strength of non-linear convective processes is expected to be larger than viscous damping, the plasma in the heliotail is turbulent. Where magnetic field domains converge on each other due to solar wind gradient, stochastic magnetic reconnection likely occurs. Such processes may be efficient enough to re-accelerate a fraction of TeV particles as long as scattering processes are not strong. Therefore, the fractional excess of TeV cosmic rays from the narrow region toward the heliotail direction traces sightlines with the lowest smearing scattering effects, that can also explain the observation of a harder than average energy spectrum.
Three-Level Switching Cell for Low Voltage/High-Current DC–DC Converters

New three-level switching cell converter topologies are proposed for transformer isolated low voltage/high current output dc-dc conversion. When compared with corresponding conventional converters without the three-level switching cell, the proposed converters operate with smaller current ripple and reduced voltage stresses. Alternatively, the current ripple size can be kept the same and the filter inductor value can be reduced for higher slew rate. First, the operation principles of these converters are described. Then converter design, control implementation and applications are presented. The capacitor charge balance problem is also addressed. Circuit simulations and experiments verify the basic operation of the new converters and their efficiency improvement.
Gene silencing by double-stranded RNA (Nobel Lecture).

I would like to thank the Nobel Assembly of the Karolinska Institute for the opportunity to describe some recent work on RNA-triggered gene silencing. First a few disclaimers, however. Telling the full story of gene silencing would be a mammoth enterprise that would take me many years to write and would take you well into the night to read. So we'll need to abbreviate the story more than a little. Second (and as you will see) we are only in the dawn of our knowledge; so consider the following to be primer ... the best we could do as of December 8th 2006. And third, please understand that the story that I am telling represents the work of several generations of biologists, chemists, and many shades in between. I'm pleased and proud that work from my laboratory has contributed to the field, and that this has led to my being chosen as one of the messengers to relay the story in this forum. At the same time, I hope that there will be no confusion of equating our modest contributions with those of the much grander RNAi enterprise.
Differential privacy for functions and functional data

Differential privacy is a rigorous cryptographically-motivated characterization of data privacy which may be applied when releasing summaries of a database. Previous work has focused mainly on methods for which the output is a finite dimensional vector, or an element of some discrete set. We develop methods for releasing functions while preserving differential privacy. Specifically, we show that adding an appropriate Gaussian process to the function of interest yields differential privacy. When the functions lie in the reproducing kernel Hilbert space (RKHS) generated by the covariance kernel of the Gaussian process, then the correct noise level is established by measuring the "sensitivity" of the function in the RKHS norm. As examples we consider kernel density estimation, kernel support vector machines, and functions in RKHSs.
A satellite system synthesis model for orbital arc allotment optimization

A mixer-integer programming formulation is presented of a satellite system synthesis problem, or geostationary-orbital-planning synthesis problem, which is referred to as the arc allotment problem (AAP). Each satellite administration is to be allotted a weighted-length segment of the geostationary orbital arc within which its satellites may be positioned at any longitude. The objective function maximizes the length of the unweighted arc segment allotted to every administration, subject to single-entry cochannel interference restrictions and constraints imposed by the visible arc for each administration. Useful relationships between special cases of AAP and another satellite synthesis problem are established. Solutions to two example problems are presented. >
Manipulating Scrip Systems: Sybils and Collusion

Game-theoretic analyses of distributed and peer-to-peer systems typically use the Nash equilibrium solution concept, but this explicitly excludes the possibility of strategic behavior involving more than one agent. We examine the effects of two types of strategic behavior involving more than one agent, sybils and collusion, in the context of scrip systems where agents provide each other with service in exchange for scrip. Sybils make an agent more likely to be chosen to provide service, which generally makes it harder for agents without sybils to earn money and decreases social welfare. Surprisingly, in certain circumstances it is possible for sybils to make all agents better off. While collusion is generally bad, in the context of scrip systems it actually tends to make all agents better off, not merely those who collude. These results also provide insight into the effects of allowing agents to advertise and loan money.