cssi/SciSciGPT-SciSciNet huggingface dataset:
Tweakable Block Ciphers

A common trend in applications of block ciphers over the past decades has been to employ block ciphers as one piece of a “mode of operation”—possibly, a way to make a secure symmetric-key cryptosystem, but more generally, any cryptographic application. Most of the time, these modes of operation use a wide variety of techniques to achieve a subgoal necessary for their main goal: instantiation of “essentially different” instances of the block cipher. We formalize a cryptographic primitive, the “tweakable block cipher.” Such a cipher has not only the usual inputs—message and cryptographic key—but also a third input, the “tweak.” The tweak serves much the same purpose that an initialization vector does for CBC mode or that a nonce does for OCB mode. Our abstraction brings this feature down to the primitive block-cipher level, instead of incorporating it only at the higher modes-of-operation levels. We suggest that (1) tweakable block ciphers are easy to design, (2) the extra cost of making a block cipher “tweakable” is small, and (3) it is easier to design and prove the security of applications of block ciphers that need this variability using tweakable block ciphers.
North polar stratigraphy and the paleo-erg of Mars

An accurate self-consistent way of coregistering the imaging and topographic data sets of the Mars Global Surveyor mission was developed and used to begin a stratigraphic analysis of the northern polar region. A distinct change in the layering style exists at a definite stratigraphic horizon near the base of the north polar layered deposits. Occurrences of the contact between two distinct layered units can be mapped hundreds of kilometers apart at nearly the same Mars Orbiter Laser Altimeter (MOLA) elevation. The lower layered unit has a consistent association with sand dunes, leading to the conclusion that it is an eroding sand-rich deposit that predates most of the overlying north polar layered deposits, which exhibits the expected features of a dust-ice mixture. These results suggest that an areally extensive erg was in existence before the present ice cap and that the present circumpolar erg is likely composed of material reworked from this older deposit. The volume of this lower unit is estimated to be on the order of 10^5 km^3. The presence of this deposit implies that there existed a period in Mars' history when there was no icy polar cap. A dramatic climatic change leading to the deposition of the upper layered (icy) unit in the present-day polar layered deposits represents a major event in Mars' history. However, owing to uncertainties in the mechanics of layered deposits formation, such an event cannot be dated at this time.
Charged drop levitators and their applications

Charged drop levitation is described for two different kinds of levitators. It is demonstrated that the feedback-controlled electrostatic levitator is capable of levitating a several milimeter size large drop in 1 g, and it can be used in various experiments such as crystal growth, supercooling and solidification, and drop dynamics. Charged droplet levitation in a vertical, linear quadrupole levitator is described, and its advantages are demonstrated taking the charged drop instability experiment as an example. The cause of the observed premature burstings are speculated to be not by the Rayleigh limit but, rather, by an electron avalanch in the surrounding gaseous medium. No evidence was found that the burtings accompaied by mass loss, in direct contrast to the most of the previous reports by Doyle et. al. and Abbas and Latham.
Risk modeling concepts relating to the design and rating of agricultural insurance contracts

The authors identify the key issues and concerns that arise in the design and rating of crop yield insurance plans, with a particular emphasis on production risk modeling. The authors show how the availability of data shapes the insurance scheme and the ratemaking procedures. Relying on the U.S. experience and recent developments in statistics and econometrics, they review risk modeling concepts and provide technical guidelines in the development of crop insurance plans. Finally, they show how these risk modeling techniques can be extended to price risk in order to develop crop revenue insurance schemes.
Densification characteristics of corn cobs

Abstract Corn cobs are potential feedstocks for producing heat, power, fuels, and chemicals. Densification of corn cobs into briquettes/pellets would improve their bulk handling, transportation, and storage properties. In this study, densification characteristics of corn cobs were studied using a uniaxial piston-cylinder densification apparatus. With a maximum compression pressure of 150 MPa, effects of particle size (0.85 and 2.81 mm), moisture content (10 and 20% w.b.), and preheating temperature (25 and 85 °C) on the density and durability of the corn cob briquettes (with diameter of about 19.0 mm) were studied. It was found that the durability (measured using ASABE tumbling can method) of corn cob briquettes made at 25 °C was 0%. At both particle sizes, preheating of corn cob grinds with about 10% (w.b.) moisture content to 85 °C produced briquettes with a unit density of > 1100 kg m -3 and durability of about 90%.
The Complexities of Fatigue in Children with Hearing Loss

Fatigue is a common phenomenon in our society, and it can have a major impact on an individual's performance and wellbeing. Parents and teachers have long believed that children with hearing loss (CHL) are at increased risk for fatigue. One could easily speculate that toward the end of a school day, CHL may be “physically and mentally spent” as a result of focusing so intently on a teacher's speech, as well as conversations with other students. Moreover, the increased listening effort, stress, and subsequent fatigue experienced by CHL could jeopardize the ability to learn in a noisy classroom environment, thus increasing the risk for problems in school. Only recently, however, have we begun to see empirical studies supporting the notion that CHL experience more fatigue than children with normal hearing (CNH). This review was developed to enhance the awareness of fatigue among those audiologists interested in serving CHL. To this end, we have presented an overview on fatigue in CHL, including its importanc...
Dynamic control of biologically inspired pulsatile jet propulsion thrusters

Inspired by the propulsion techniques employed by squid and other cephalopod, a new type of thruster was designed which utilized pulsatile jet propulsion to generate controlling forces. The thrust production from this jet actuator was characterized in a static environment and seen to be well approximated by a simple fluid slug model. A linear transfer function model was derived to describe the transient dynamics of this thruster being employed in a virtual vehicle simulation; which was developed to test the thruster with unsteady driving signals. It was predicted that an impulsive type of thrust (as is found in our jet actuator) is ideal in a non-linear damping environment, since all of the acceleration is being added to the system while it's at its lowest velocity and therefore lowest drag. Due to the extremely non-linear nature of underwater vehicle environments we developed a scaling system to classify regimes of maneuvers and characterize their dynamics independently. Assuming a simple proportional derivative control algorithm, the vehicle closed loop frequency response was predicted using the transfer function model; which was linearized according to the maneuvering regime. Within the hybrid simulation environment, the closed loop frequency response was tested empirically and seen to be well approximated by the model.
The Cut and Paste Society: Isomorphism in Codes of Ethics

Regulatory responses to the business failures of 1998–2001 framed them as a general failure of governance and ethics rather than as firm-specific problems. Among the regulatory responses are Section 406 of Sarbanes–Oxley Act, SEC, and exchange requirements to provide a Code of Ethics. However, institutional pressures surrounding this regulation suggest the potential for symbolic responses and decoupling of response from organizational action. In this article, we examine Codes of Ethics for a stratified sample of 75 U.S. firms across five distinct industries and find that content and language converge across organizations in ways undesired by the regulators, and that language is used to minimize the effects of the Code on constraining organizational behavior. There is, however, a noteworthy exception in the sections of the Codes dedicated the ethics of financial reporting. Although this material still contains legalistic boilerplate information, it does offer concrete guidance and emphatic language pertaining to the need to maintain the integrity of reporting practices. This suggests that the corporate understanding of the source of the failures is one of fraudulent financial reporting. Aside from the matter of financial reporting, the vague and stylized content of the Codes was a predicted response and constitutes a rational response to the regulation. The regulation, however, clearly states the belief that Codes should vary from firm to firm and that individual firms should determine the specific content of a Code. Aside from financial reporting matters, the observed result suggests that regulatory efforts may have failed to instigate corporate change in attitudes toward and enforcement of higher ethical standards by corporate actors.
Primordial nucleosynthesis and the abundances of beryllium and boron

The recently attained ability to make measurements of Be and B as well as to put constraints on Li-6 abundances in metal-poor stars has led to a detailed reexamination of big bang nucleosynthesis in the A is greater than about 6 regime. The nuclear reaction network has been significantly expanded, with many new rates added. It is demonstrated that although a number of A is greater than 7 reaction rates are poorly determined, even with extreme values chosen, the standard homogeneous model is unable to produce significant yields above A = 7, and the (Li-7)/(Li-6) ratio always exceeds 500. We also preliminarily explore inhomogeneous models, such as those inspired by a first-order quark-hadron phase transition, where regions with high neutron/proton ratios can allow some leakage up to A is greater than 7. However, models that fit the A is not greater than 7 abundances still seem to have difficulty in obtaining significant A is greater than 7 yields.
Eigenvalue bounds, spectral partitioning, and metrical deformations via flows

We present a new method for upper bounding the second eigenvalue of the Laplacian of graphs. Our approach uses multi-commodity flows to deform the geometry of the graph; we embed the resulting metric into Euclidean space to recover a bound on the Rayleigh quotient. Using this, we show that every n-vertex graph of genus g and maximum degree D satisfies λ2(G)=O((g+1)3D/n). This recovers the O(D/n) bound of Spielman and Teng for planar graphs, and compares to Kelner's bound of O((g+1)poly(D)/n), but our proof does not make use of conformal mappings or circle packings. We are thus able to extend this to resolve positively a conjecture of Spielman and Teng, by proving that λ2(G) = O(Dh6log h/n) whenever G is Kh-minor free. This shows, in particular, that spectral partitioning can be used to recover O(√n)-sized separators in bounded degree graphs that exclude a fixed minor. We extend this further by obtaining nearly optimal bounds on λ2 for graphs that exclude small-depth minors in the sense of Plotkin, Rao, and Smith. Consequently, we show that spectral algorithms find separators of sublinear size in a general class of geometric graphs. Moreover, while the standard “sweep” algorithm applied to the second eigenvector may fail to find good quotient cuts in graphs of unbounded degree, our approach produces a vector that works for arbitrary graphs. This yields an alternate proof of the well-known nonplanar separator theorem of Alon, Seymour, and Thomas that states that every excluded-minor family of graphs has O(√n)-node balanced separators.
Quantum anomalous Hall effect with cold atoms trapped in a square lattice

We propose an experimental scheme to realize the quantum anomalous Hall effect in an anisotropic square optical lattice which can be generated from available experimental setups of double-well lattices with minor modifications. A periodic gauge potential induced by atom-light interaction is introduced to give a Peierls phase for the nearest-neighbor site hopping. The quantized anomalous Hall conductivity is investigated by calculating the Chern number as well as the chiral gapless edge states of our system. Furthermore, we show in detail the feasability for its experimental detection through light Bragg scattering of the edge and bulk states with which one can determine the topological phase transition from usual insulating phase to quantum anomalous Hall phase.
The Standard of Care Is Not So Standard

Malpractice lawsuits affect most physicians at some point in their career. Proving that malpractice has been committed is based on substantiation of a variety of elements, including that the patient was rendered care that was "below the standard" of care. While many physicians believe that the "standard" will be judged objectively on the basis of published scientific sources and accepted conventions, the standard is established rather by the testimony of expert witness(es). It is the expert testimony that sets the standard and is proof of the standard. The testimony is open for acceptance or rejection by the judge or jury for a variety of nonscientific reasons. We review what the defendant doctor might expect regarding proof required to establish breach of the standard of care and what the prudent expert should be obliged to demonstrate.
Using Tax Policy To Curb Speculative Short-Term Trading

This article addresses the question of the desirability of a tax on transactions in the securities industry. Many of the other major industrialized economies impose such a tax. In Japan, for instance, the tax raises $12 billion a year (see Roll, 1989). I propose to consider the consequences of a tax at a relatively low rate, say .5 percent to 1 percent of the value of the transactions.1
Optimal and suboptimal detection of Gaussian signals in noise: asymptotic relative efficiency

The performance of Bayesian detection of Gaussian signals using noisy observations is investigated via the error exponent for the average error probability. Under unknown signal correlation structure or limited processing capability it is reasonable to use the simple quadratic detector that is optimal in the case of an independent and identically distributed (i.i.d.) signal. Using the large deviations principle, the performance of this detector (which is suboptimal for non-i.i.d. signals) is compared with that of the optimal detector for correlated signals via the asymptotic relative efficiency defined as the ratio between sample sizes of two detectors required for the same performance in the large-sample-size regime. The effects of SNR on the ARE are investigated. It is shown that the asymptotic efficiency of the simple quadratic detector relative to the optimal detector converges to one as the SNR increases without bound for any bounded spectrum, and that the simple quadratic detector performs as well as the optimal detector for a wide range of the correlation values at high SNR.
WiSyMon: managing systems monitoring information in semantic Wikis

The work presented in the poster describes our collaborative approach to managing systems monitoring information in a Semantic Wiki. This allows to extend the applicability of managing systems monitoring information from IT personnel to IT-knowledgeable users (e.g., developers, or researchers). Semantic relations edited in the Semantic Wiki are translated into systems monitoring configuration files used by an external application. Information about the status of services and hosts is inserted into the Wiki.
Pediatric decision support using adapted Arden Syntax.

Abstract Background Pediatric guidelines based care is often overlooked because of the constraints of a typical office visit and the sheer number of guidelines that may exist for a patient's visit. In response to this problem, in 2004 we developed a pediatric computer based clinical decision support system using Arden Syntax medical logic modules (MLM). Methods The Child Health Improvement through Computer Automation system (CHICA) screens patient families in the waiting room and alerts the physician in the exam room. Here we describe adaptation of Arden Syntax to support production and consumption of patient specific tailored documents for every clinical encounter in CHICA and describe the experiments that demonstrate the effectiveness of this system. Results As of this writing CHICA has served over 44,000 patients at 7 pediatric clinics in our healthcare system in the last decade and its MLMs have been fired 6182,700 times in “produce” and 5334,021 times in “consume” mode. It has run continuously for over 10 years and has been used by 755 physicians, residents, fellows, nurse practitioners, nurses and clinical staff. There are 429 MLMs implemented in CHICA, using the Arden Syntax standard. Studies of CHICA's effectiveness include several published randomized controlled trials. Conclusions Our results show that the Arden Syntax standard provided us with an effective way to represent pediatric guidelines for use in routine care. We only required minor modifications to the standard to support our clinical workflow. Additionally, Arden Syntax implementation in CHICA facilitated the study of many pediatric guidelines in real clinical environments.
Stabilization of a cascade-connected nonlinear system with an input constraint

This paper focuses on the problem of stabilization of a nonlinear system with an input constraint. We provide a universal control formula for a cascade-connected nonlinear system with an input constraint and confirm the effectiveness of proposed method by computer simulation.
Don't Panic! Closed String Tachyons in ALE Spacetimes

We consider closed string tachyons localized at the fixed points of noncompact nonsupersymmetric orbifolds. We argue that tachyon condensation drives these orbifolds to flat space or supersymmetric ALE spaces. The decay proceeds via an expanding shell of dilaton gradients and curvature which interpolates between two regions of distinct angular geometry. The string coupling remains weak throughout. For small tachyon VEVs, evidence comes from quiver theories on D-branes probes, in which deformations by twisted couplings smoothly connect non-supersymmetric orbifolds to supersymmetric orbifolds of reduced order. For large tachyon VEVs, evidence comes from worldsheet RG flow and spacetime gravity. For 2/n, we exhibit infinite sequences of transitions producing SUSY ALE spaces via twisted closed string condensation from non-supersymmetric ALE spaces. In a T-dual description this provides a mechanism for creating NS5-branes via closed string tachyon condensation similar to the creation of D-branes via open string tachyon condensation. We also apply our results to recent duality conjectures involving fluxbranes and the type 0 string.
A note on finite abelian gerbes over toric Deligne-Mumford stacks

This is the published version, also available here: http://dx.doi.org/10.1090/S0002-9939-08-09461-6. First published in Proc. Amer. Math. Soc. in 2015, published by the American Mathematical Society.
Analysis Tools for the Detection of Intermittent Nonlinear Aeroelastic Phenomena

The nonlinear coupling between the aerodynamic load and structural motions in the experiments conducted in the Langley Transonic Dynamics Tunnel at NASA Langley Research Center on a flexible semispan model (FSM) of a high-speed civil transport wing configuration is examined. The results show that, right before "hard" flutter took place, the aerodynamic load and the structural motion of the FSM were intermittently and quadratically coupled. Particularly, the shock motion, which can be caused by local and intermittent flow separation, is nonlinearly related to the structural motion in such a manner that one full cycle of the shock motion is related to two cycles of the acceleration of the wing tip. Because of the required averaging in implementing them, Fourier-based higher-order spectral moments could not characterize this coupling. On the other hand, the wavelet-based cross bicoherence is established as a tool that is capable of detecting intermittent or transient nonlinear aeroelastic phenomena as would be encountered in model studies or flight tests.
Maintenance as a function of design

Changing one's point of view on the maintenance function can lead to a better understanding of the relationship between maintenance and other aspects of software products. This can lead to an improved allocation of effort when building software products.
Improved approximations for multiprocessor scheduling under uncertainty

This paper presents improved approximation algorithms for the problem of multiprocessor scheduling under uncertainty (SUU), in which the execution of each job may fail probabilistically. This problem is motivated by the increasing use of distributed computing to handle large, computationally intensive tasks. In the SUU problem we are given n unit-length jobs and m machines, a directed acyclic graph G of precedence constraints among jobs, and unrelated failure probabilities qij for each job j when executed on machine i for a single timestep. Our goal is to find a schedule that minimizes the expected makespan.Lin and Rajaraman gave the first approximations for this NP-hard problem for the special cases of independent jobs, precedence constraints forming disjoint chains, and precedence constraints forming trees. In this paper, we present asymptotically better approximation algorithms. In particular, we improve upon the previously best O(log n)-approximation, giving an O(log log(min {m,n}))-approximation in the case of independent jobs. We also give an O(log(n+m) log log(min{m,n}))-approximation algorithm for precedence constraints that form disjoint chains (improving on the previously best O(log(n)log(m) log(n+m) over log log(n+m)-approximation by a (log n/log log n)2 factor when n = mΘ(1)). Our algorithm for precedence constraints forming chains can also be used as a component for precedence constraints forming trees, yielding a similar improvement over the previously best algorithms for trees.Our techniques include reducing SUU to a problem in stochastic scheduling, where machines must process a set of jobs with randomly distributed lengths. We show that our algorithms for (SUU) apply to a standard problem in this setting, giving the first approximation algorithms for preemptive stochastic scheduling on unrelated machines.
Postischemic deterioration of sarcoplasmic reticulum: Warm versus cold blood cardioplegia

Abstract Impaired cardiac sarcoplasmic reticulum (SR) function, as evidenced by reduced SR Ca 2+ uptake rate and decreased SR Ca 2+ -adenosine triphosphatase activity, has been found in postischemic "stunned" myocardium and in hearts subjected to hypothermic arrest. In this study, we compared the effects of retrograde continuous coronary sinus warm blood cardioplegia (WBC) and retrograde intermittent cold blood cardioplegia (CBC) on cardiac SR function and postischemic ventricular functional recovery in pig hearts. Twelve in situ isolated pig hearts supported by cardiopulmonary bypass were subjected to 120 minutes of cardioplegic arrest with either WBC (37 °C or CBC (6 ° to 10 °C), followed by 60 minutes of 37 °C reperfusion. Left ventricular global contractile function and coronary blood flow were measured before arrest and during reperfusion. Cardiac SR was isolated from left ventricular biopsy specimens, and 45 Ca 2+ uptake by SR and SR Ca 2+ -adenosine triphosphatase activity were determined. The recovery of left ventricular global contractile function as indicated by the maximum of the first derivative of left ventricular pressure was significantly improved in the WBC group compared with that of the CBC group (70% versus 46%; P 2+ -adenosine triphosphatase activity was better preserved after 60 minutes reperfusion in WBC compared with CBC (0.31 ± 0.02 versus 0.20 ± 0.03 μM Pi/min/mg protein, p 2+ uptake was significantly improved by WBC compared with CBC (1.15 ± 0.12 versus 0.83 ± 0.04 μM Ca 2+ /min/mg protein; p 2+ homeostasis.
Anhydrous solution synthesis of germanium nanocrystals from the germanium(II) precursor Ge[N(SiMe3)2]2

A convenient, simple, single-source solution synthesis of Ge nanocrystals via thermal reduction of Ge(II) precursor Ge[N(SiMe3)2]2 in a non-coordinating solvent at 300 °C and 1 atm Ar is described.
Explicit gradient estimates for minimal Lagrangian surfaces of dimension two

We derive explicit, uniform, a priori interior Hessian and gradient estimates for special Lagrangian equations of all phases in dimension two.
Health Human Capital and Economic Development

Lifespan has doubled in the world in the last 200 years. In the last 50 years, this advance in health, measured by expectation of life at birth, has been shared more equally among people than the increase in income. The record of this concurrent increase in lifespan and income per capita suggests it may be important to understand how these events are interrelated. The connections between health and development are controversial, in part because the evidence on this topic comes from different scientific disciplines, answering different questions, relying on different types of data and using different analytical methods. However, hypotheses are emerging that merit much more study in Africa and elsewhere, to guide the allocation of resources for health, which will entail refinement of conceptual frameworks to isolate causal relationships through more rigorous empirical testing, and collection of new data for more decisive tests. Two types of relationships are distinguished: first, the linkages between conditions under which people live and their expected lifespan and health status, which characterise the technology of ‘health production functions’; second, the relationship between an individual's stock of health and her or his economic productivity, well-being and duration of life, which characterise ‘returns to health human capital’. In the last 50 years, the lifespan at birth of the relatively rich and poor converged, at least until the 1990s. There are indications that this was achieved mainly by improvements in nutrition and control of infectious diseases concentrated in childhood that were relatively cheap to disseminate. To control mortality and reduce disability among adults confronting degenerative chronic diseases has proved more costly, and the relatively poor may thus not benefit as much as the rich from the dissemination of these newer medical technologies unless subsidised. However, the prior reduction in childhood illnesses may itself contribute to improved adult health outcomes later in the life cycle. Birth cohorts which have experienced diminished infections and inflammatory illnesses in utero and early childhood and received better early nutrition may also increase their potential economic productivity as adults, as well as live longer lives free of disability.
Modeling Wage Inequality in the U.S. as Conditional Variation: A Time Series Approach

Abstract In this paper, we argue that wage volatility is a good proxy for wage inequality because of the strong and lagged correlation between the two. For six industry categories, inequality is modeled as a conditional variance process over the period 1964–1988. It is modified to allow for explanatory variables that have a robust theoretical basis for inclusion as determinants of wage inequality. One of the major findings is the identification of the major contributors to rising U.S. wage inequality in the 1980s: the declining real value of the minimum wage, the loss of collective bargaining gains by labor, and immigration.
Dynamic Compensation of Intelligent Sensors

Commercial sensors have generally, due to their own characteristics, some undesirable influences on the measured quantity and its precision. In particular, the dynamic characteristics can be reflected on to the measured quantity and lead to false or delayed interpretation of the underlying physical process. The quality and, therefore, the cost of the sensor are often tied to the dynamic performance of these instruments. Intelligent sensors are able to adapt to changing environments, calibrate themselves, and predict the pattern of the future signal. This paper presents algorithms to improve the dynamic performance of sensors, to identify the dynamic characteristics of the sensor, and to predict the future pattern of the measured quantity. In particular, two inverse filters are proposed for the improvement of the sensors dynamic performance. One filter incorporates an optimal constant feedback gain that reduces the computational cost and increases the accuracy. A system identification method is used to identify the sensors dynamic properties and allows for adaptation of the inverse filters parameters. This identification algorithm computes the optimum input to the system, i.e., the sensor. The optimization is based on the inverse covariance matrix of the information matrix. A genetic algorithm is used to perform both optimizations for the computation of the optimal input and for the optimal constant feedback gain. In addition, a predictive filter formulation is given that is based on the identified system. Simulation results indicate that both inverse filters are capable of recovering the original or true signal. The second filter shows superiority in terms of convergence, lower computational cost, and lower error due to its optimized parameters. The predictive filter indicates good working accuracy for the signal prediction.
Orderly Sovereign Debt Restructuring : Missing in Action!

This paper takes a hard look at the experience with official intervention in sovereign debt crises, focusing on debt crises of the 1980s, Russia in 1998, Argentina in 2001, and Greece in 2010. Based on the track record, the authors argue that in situations where countries face a solvency problem, official intervention is more likely to succeed if official money is lent at the risk-free rate reflecting its seniority and private creditors receive an upfront haircut. Such an approach would limit the costs associated with procrastination and increase the chances of success by enabling a more realistic fiscal program to restore solvency. They examine the moral hazard implications for debtor countries of this proposal and find that these are unlikely to be severe. In fact, after their crises of 1997-2001, emerging market countries embarked on an aggressive and comprehensive program of self-insurance, indicating that they are weary of debt crises and their costs. However, the prospect of an upfront haircut for private creditors in the event of insolvency is likely to make them more diligent in their sovereign lending decisions.
Surface roughness evaluation via ultrasonic scanning

Despite extensive applications of ultrasonic waves to various nondestructive testing and evaluation of materials, scattering of focused ultrasonic waves due to surface roughness has not been fully investigated. This paper presents an analytical and experimental evaluation of surface roughness measurement using focused ultrasonic beams. The characteristics of focused ultrasonic waves are analyzed by using the impulse response method with a sine-modulated Gaussian pulse as source. First, the beam profile in the focal plane of the focused ultrasonic transducer is analyzed both numerically and experimentally. Second, peak amplitude distribution and reflected waveforms from a flat surface with various incident angles are analytically generated and compared with experimental results. Then, the peak amplitudes of the ultrasonic waves reflected from cusped surfaces which are easily found among machined surfaces are analyzed and compared with experimental data for the first time. The analysis shows good agreement between analytical and experimental results. The excellent correlation between the measurements using a profilometer and the proposed ultrasonic system demonstrates a good potential for surface roughness measurement by ultrasonic sensing. >
Consensus problem under diffusion-based molecular communication

We investigate the consensus problem in a network where nodes communicate via diffusion-based molecular communication (DbMC). In DbMC, messages are conveyed via the variation in the concentration of molecules in the medium. Every node acquires sensory information about the environment. Communication enables the nodes to reach the best estimate for that measurement, e.g., the average of the initial estimates by all nodes. We consider an iterative method for communication among nodes that enables information spreading and averaging in the network. We show that the consensus can be attained after a finite number of iterations and variance of estimates of nodes can be made arbitrarily small via communication.
Comment on Article by Gates

I congratulate Jerry Gates on a lucid and important discussion of the role of privacy and confidentiality in sharing government data. He makes a strong case that increased and easier data sharing would improve the collection, estimation, and dissemination of federal data—which in turn would lead to better research and public policy—and that confidentiality concerns raise barriers to realizing those benefits. His suggestion for a multi-faceted approach based on legal reform, inter-agency cooperation, and methodological research is a solid path for finding ways to lower the barriers.
TESTING MODELS OF ACCRETION-DRIVEN CORONAL HEATING AND STELLAR WIND ACCELERATION FOR T TAURI STARS

Classical T Tauri stars are pre-main-sequence objects that undergo simultaneous accretion, wind outflow, and coronal X-ray emission. The impact of plasma on the stellar surface from magnetospheric accretion streams is likely to be a dominant source of energy and momentum in the upper atmospheres of these stars. This paper presents a set of models for the dynamics and heating of three distinct regions on T Tauri stars that are affected by accretion: (1) the shocked plasmas directly beneath the magnetospheric accretion streams, (2) stellar winds that are accelerated along open magnetic flux tubes, and (3) closed magnetic loops that resemble the Sun's coronal active regions. For the loops, a self-consistent model of coronal heating was derived from numerical simulations of solar field-line tangling and turbulent dissipation. Individual models are constructed for the properties of 14 well-observed stars in the Taurus-Auriga star-forming region. Predictions for the wind mass-loss rates are, on average, slightly lower than the observations, which suggests that disk winds or X-winds may also contribute to the measured outflows. For some of the stars, however, the modeled stellar winds do appear to contribute significantly to the measured mass fluxes. Predictions for X-ray luminosities from the shocks and loops are in general agreement with existing observations. The stars with the highest accretion rates tend to have X-ray luminosities dominated by the high-temperature (5-10 MK) loops. The X-ray luminosities for the stars having lower accretion rates are dominated by the cooler accretion shocks.
An adaptive actuator failure compensation controller using output feedback

An adaptive control scheme using output feedback for output tracking is developed for systems with unknown actuator failures. Such actuator failures are characterized by some unknown inputs stuck at some unknown fixed values at unknown time instants. An effective output feedback controller structure is proposed for actuator failure compensation. When implemented with true matching parameters, the controller achieves desired plant-model output matching. When implemented with adaptive parameter estimates, the controller achieves asymptotic output tracking. A stable adaptive law is derived for parameter adaptation in the presence of parameter uncertainties. Closed-loop signal boundedness and asymptotic output tracking, despite the uncertainties in actuator failures and plant parameters, are ensured analytically and verified by simulation results.
Breakup of the weakly bound 17F nucleus

The breakup of the radioactive 17 F nucleus into a proton and 16 O is studied for the reaction 17 F + 208 Pb → p + 16 O + 208 Pb at 65 MeV/nucleon. The possibility of using this reaction as a test case for studying dynamical Coulomb reacceleration effects is assessed. It is shown that the reaction is dominated by elastic nuclear breakup (diffraction dissociation).  2003 Elsevier Science B.V. All rights reserved.
A different look at output tracking: control of a VTOL aircraft

Abstract In this paper we propose a scheme for output tracking of nonminimum phase flat systems. The technique, which is applicable even in the minimum phase case, uses an inverse trajectory for feedforward which is stabilized by a state tracker built using the flat output. In contrast to approximate-linearization based control [Hauser, J., S. Sastry and G. Meyer (1992). Nonlinear control design for slightly nonminimum phase systems: application to v/stol aircraft. Automatica, 28, 665–679], which yields good performance in slightly nonminimum phase systems, our approach applies equally well to slightly and strongly nonminimum phase systems. The proposed control scheme and the approximate-linearization based controller are applied to a Vertical Take Off and Landing (VTOL) aircraft example and the performances are compared.
Super-resolution imaging using spatial fourier transform infrared spectroscopy

We describe a scheme for far-field subwavelength spectroscopy and imaging in the mid-IR and THz bands. This approach is based on scattering from an acoustic grating and can recover both the amplitude and the phase of the incident field.
DETECTION AND IDENTIFICATION OF MICROORGANISMS IN MIXED CULTURES BY NANOPARTICLE-INDUCED NANOSPR ENHANCED FTIR SPECTROSCOPY AND CHEMOMETRICS

Routine identification of pathogenic microorganisms predominantly based on nutritional and biochemical tests is a time-consuming process, but delay may lead to fatal consequences at times. In this work, nanoparticle-induced nanoSPR enhanced IR spectroscopy was used in conjunction with a background elimination data processing algorithm to directly identify microorganisms in mixed cultures. It was demonstrated that the microbial composition of mixtures of different E. coli strains could be accurately identified using our method, at a concentration level of 103 CFU mL -1 . The procedure was also applied to determine the presence or absence of pathogenic microorganisms in a simple but real food matrix (apple juice). Results indicated that microorganisms in a cocktail of up to eight different species suspended in an apple juice matrix could be accurately identified for its presence or absence.
Do Investment Banks' Relationships with Investors Impact Pricing? The Case of Convertible Bond Issues

This study examines the role of repeat interactions between placement agents (investment banks) and investors in the initial pricing of convertible bonds. Under the assumption that attracting repeat investors can reduce search frictions in primary issue markets, we test the hypothesis that banks' relationships with investors actually allow more favorable pricing for issuing firms (in contrast to the “favoritism” hypothesis, under which banks use underpricing to reward favored clients). In the empirical analysis we also allow for a potentially important alternative channel through which search frictions might impact initial pricing: expected after-market liquidity. Using a sample of 601 Rule 144A issues for the years 1997--2007, we document robust negative relationships between at-issue discounts and both types of frictions. Our findings suggest that search frictions play a meaningful role in initial convertible bond pricing and, specifically, that intermediaries can add substantial value through repeated interactions with investors. This paper was accepted by Brad Barber, finance.
The physics and modes of star cluster formation: observations

Stellar clusters are born in cold and dusty molecular clouds and the youngest clusters are embedded to various degrees in a dusty dark molecular material. Such embedded clusters can be considered protocluster systems. The most deeply buried examples are so heavily obscured by dust that they are only visible at infrared wavelengths. These embedded protoclusters constitute the nearest laboratories for a direct astronomical investigation of the physical processes of cluster formation and early evolution. I review the present state of empirical knowledge concerning embedded-cluster systems and discuss the implications for understanding their formation and subsequent evolution to produce bound stellar clusters.
Corporate Capital Budgeting Decisions and Information Sharing

Firms must overcome agency and information asymmetry problems to make efficient corporate capital budgeting decisions; this is particularly true for firms with multiple units dispersed across geographic locations. Internal communication and coordination may therefore be crucial in reducing information asymmetry and achieving efficient resource allocation. We examine the relationship between corporate capital budgeting decisions and the degree of internal information sharing using a dataset of 342 U.S. firms from 1993 to 2002. Information sharing is measured by the internal linkages observed in firms’ research and development activities worldwide. The efficiency of a firm’s capital budgeting decisions is measured by the deviation of the firm’s estimated marginal q from the theoretical tax-adjusted benchmark. We observe a significant relationship between value-enhancing capital budgeting decisionsandstrongerinternallinkages.Specifically,corporateoverinvestment issignificantlyreducedwithbetterinformationsharingacrossunits.Allresults are robust to firm- and industry-level controls.
Rational Objective Functions for Vehicles

Although energy is the key resource for achieving vehicle performance desiderata, it is not necessary, nor is it necessarily desirable, to assess the desiderata in terms of energy alone. Yet, because the energy conversion systems in vehicles may use or supply energy in several forms (thrust, power, heat, cooling, etc. ), exergy must be used to account for energy-based interactions between systems and for the costing of various “ streams” (mass, power, etc.). Exergy is the key to the decomposition of energy systems and allows concurrent engineering of the several devices that may make up an overall system. One proposed method for creating an overall objective function is presented. Then, the methods of thermoeconomics will be combined with it to allow decomposition and detailed design of subsystems and devices. As an example, objective functions and weighting factors will be developed for a light experimental aircraft. Decomposition will be illustrated with the selection of an alternator and engine. Nomenclature A = area AR = aspect ratio C = lift or drag coefe cient c = unit cost D = desideratum F = feed F = force g = acceleration of gravity J = total cost m = mass P = product; power R = range T = time weighting factor V = velocity v = unit value W = weighting factor P X = exergyeow Z = capital 5 = proet Ω = density Subscripts D = drag f = feed L = lift m = mass p = product T = thrust
GRADE: Machine Learning Support for Graduate Admissions

This article describes GRADE, a statistical machine learning system developed to support the work of the graduate admissions committee at the University of Texas at Austin Department of Computer Science (UTCS). In recent years, the number of applications to the UTCS PhD program has become too large to manage with a traditional review process. GRADE uses historical admissions data to predict how likely the committee is to admit each new applicant. It reports each prediction as a score similar to those used by human reviewers, and accompanies each by an explanation of what applicant features most influenced its prediction. GRADE makes the review process more efficient by enabling reviewers to spend most of their time on applicants near the decision boundary and by focusing their attention on parts of each applicant’s file that matter the most. An evaluation over two seasons of PhD admissions indicates that the system leads to dramatic time savings, reducing the total time spent on reviews by at least 74 percent.
GABA(A) receptors containing (alpha)5 subunits in the CA1 and CA3 hippocampal fields regulate ethanol-motivated behaviors: an extended ethanol reward circuitry.

GABA receptors within the mesolimbic circuitry have been proposed to play a role in regulating alcohol-seeking behaviors in the alcohol-preferring (P) rat. However, the precise GABA A receptor subunit(s) mediating the reinforcing properties of EtOH remains unknown. We examined the capacity of intrahippocampal infusions of an α5 subunit-selective (∼75-fold) benzodiazepine (BDZ) inverse agonist [i.e., RY 023 (RY) (tert-butyl 8-(trimethylsilyl) acetylene-5,6-dihydro-5-methyl-6-oxo-4H-imidazo [1,5a] [1,4] benzodiazepine-3-carboxylate)] to alter lever pressing maintained by concurrent presentation of EtOH (10% v/v) and a saccharin solution (0.05% w/v). Bilateral (1.5–20 μg) and unilateral (0.01–40 μg) RY dose-dependently reduced EtOH-maintained responding, with saccharin-maintained responding being reduced only with the highest doses (e.g., 20 and 40 μg). The competitive BDZ antagonist ZK 93426 (ZK) (7 μg) reversed the RY-induced suppression on EtOH-maintained responding, confirming that the effect was mediated via the BDZ site on the GABA A receptor complex. Intrahippocampal modulation of the EtOH-maintained responding was site-specific; no antagonism by RY after intra-accumbens [nucleus accumbens (NACC)] and intraventral tegmental [ventral tegmental area (VTA)] infusions was observed. Because the VTA and NACC contain very high densities of α1 and α2 subunits, respectively, we determined whether RY exhibited a “negative” or “neutral” pharmacological profile at recombinant α1β3γ2, α2β3γ2, and α5β3γ2 receptors expressed in Xenopus oocytes. RY produced “classic” inverse agonism at all α receptor subtypes; thus, a neutral efficacy was not sufficient to explain the failure of RY to alter EtOH responding in the NACC or VTA. The results provide the first demonstration that the α5-containing GABA A receptors in the hippocampus play an important role in regulating EtOH-seeking behaviors.
Study of near-field vibration sources for the NLC linac components

The vibration stability requirements for the Next Linear Collider (NLC) are far more stringent than for the previous generation of colliders. To meet these goals, it is imperative that the effects of vibration on NLC linac components from near-field sources (e.g. compressors, high vacuum equipment, klystrons, modulators, pumps, fans, etc) be well understood. The civil construction method, whether cut-and-cover or parallel bored tunnels, can determine the proximity and possible isolation of noise sources. This paper presents a brief summary and analysis of recently completed and planned studies for characterization of near-field vibration sources under either construction method. The results of in-situ vibration measurements will also be included.