cssi/SciSciGPT-SciSciNet huggingface dataset:
Bandwidth guaranteed multicast scheduling for virtual output queued packet switches

Multicast enables efficient data transmission from one source to multiple destinations, and has been playing an important role in Internet multimedia applications. Although several multicast scheduling schemes for packet switches have been proposed in the literature, they usually aim to achieve only short multicast latency and high throughput without considering bandwidth guarantees. However, fair bandwidth allocation is critical for the quality of service (QoS) of the network, and is necessary to support multicast applications requiring guaranteed performance services, such as online audio and video streaming. This paper addresses the issue of bandwidth guaranteed multicast scheduling on virtual output queued (VOQ) switches. We propose the Credit based Multicast Fair scheduling (CMF) algorithm, which aims at achieving not only short multicast latency but also fair bandwidth allocation. CMF uses a credit based strategy to guarantee the reserved bandwidth of an input port on each output port of the switch. It keeps track of the difference between the reserved bandwidth and actually received bandwidth, and minimizes the difference to ensure fairness. Moreover, in order to fully utilize the multicast capability provided by the switch, CMF lets a multicast packet simultaneously send transmission requests to multiple output ports. In this way, a multicast packet has more chances to be delivered to multiple destination output ports in the same time slot and thus to achieve short multicast latency. Extensive simulations are conducted to evaluate the performance of CMF, and the results demonstrate that CMF achieves the two design goals: fair bandwidth allocation and short multicast latency.
Majority preference for subsidies over redistribution

Abstract Among other activities, democratic governments redistribute resources directly through tax schemes that explicitly benefit the poor and indirectly through subsidizing particular goods and services that do not. Indeed, in some cases the effective redistribution under subsidy policies is clearly away from the poor. This paper studies when a majority might prefer subsidy policies over direct income redistribution in economies with mean greater than median income. The main result is a set of necessary and sufficient conditions for subsidies to be majority preferred to direct redistribution: in sum, subsidies are strictly majority preferred to redistribution when the gap between median and mean incomes is not ‘too great’.
Coordination of carboxamido nitrogen to tervalent iron:insight into a new chapter of iron chemistry

Although coordination of carboxamido nitrogen to Fe(III) center has been assumed to be improbable, research work during the past few years has demonstrated that Fe(III) complexes with ligated carboxamido nitrogens can be readily synthesized. The Fe(III)–Namido bond distances lie in the range of 1.8–2.2 A in the various low spin and high spin Fe(III) complexes. These complexes are stable in aqueous media and their redox parameters indicate that the carboxamido nitrogens provide significant stability to the Fe(III) center.
Models of the in Situ Formation of Detected Extrasolar Giant Planets

Abstract We present numerical simulations of the formation of the planetary companions to 47 UMa, ρ CrB, and 51 Peg. They are assumed to have formed in situ according to the basic model that a core formed first by accretion of solid particles, then later it captured substantial amounts of gas from the protoplanetary disk. In most of the calculations we prescribe a constant accretion rate for the solid core. The evolution of the gaseous envelope is calculated according to the following assumptions: (1) it is in quasi-hydrostatic equilibrium, (2) the gas accretion rate is determined by the requirement that the outer radius of the planet is the place at which the thermal velocity of the gas allows it to reach the boundary of the planet's Hill sphere, (3) the gas accretion rate is limited, moreover, by the prescribed maximum rate at which the nebula can supply the gas, and (4) the growth of the planet stops once it obtains approximately the minimum mass determined from radial velocity measurements (in one case the planet is allowed to grow to twice this limit). Calculations are carried out through an initial phase during which solid accretion dominates, past the point of crossover when the masses of solid and gaseous material are equal, through the phase of rapid gas accretion, and into the final phase of contraction and cooling at constant mass. Alternative calculations are presented for the case of 47 UMa in which the solid accretion rate is calculated, not assumed, and the dissolution of planetesimals within the gaseous envelope is considered. In all cases there is a short phase of high luminosity (10 −3 –10 −2 L ⊙ ) associated with rapid gas accretion. The height and duration of this peak depend on uncertain model parameters. The conclusion is reached that in situ formation of all of these companions is possible under some conditions. However, it is more likely that orbital migration was an important component of the evolution, at least for the planets around ρ CrB and 51 Peg.
The Shaping of a National Ignition Campaign Pulsed Waveform

Abstract The National Ignition Facility (NIF) at Lawrence Livermore National Laboratory is a stadium-sized facility containing a 192 beam, 1.8 MJ, 500 TW ultraviolet laser system used for inertial confinement fusion research. For each experimental shot, NIF must deliver a precise amount of laser power on the target for successful and efficient target ignition, and these characteristics vary depending on the physics of the particular campaign. The precise temporal shape, energy and timing characteristics of a pulsed waveform target interaction are key components in meeting the experimental goals. Each NIF pulse is generated in the Master Oscillator Room (MOR) using an electro-optic modulator to vary the intensity of light in response to an electrical input. The electrical drive signal to the modulator is produced using a unique, high-performance arbitrary waveform generator (AWG). This AWG sums the output of 140 electrical impulse generators, each producing a 300 ps pulse width Gaussian signal separated in time by 250 ps. By adjusting the amplitudes and summing the 140 impulses, a pulsed waveform can be sculpted from a seed 45 ns square pulse. Using software algorithms written for NIF's Integrated Computer Control System (ICCS), the system is capable of autonomously shaping 48 unique experimental pulsed waveforms for each shot that have demonstrated up to 275:1 contrast ratio with ±3% absolute error averaged over any 2 ns interval, meeting the stringent pulse requirements needed to achieve ignition. In this paper, we provide an overview of the pulse shaping system, software algorithms and associated challenges that have been overcome throughout the evolution of the controls.
Two new developments in the theory of high Tc superconductivity

Abstract Two new developments in the theory of high Tc superconductivity which explain experimental anomalies are described: First, an explanation of some striking anomalies in the angle resolved photoemission excitation spectrum provides experimental evidence for the composite nature of electronic excitations; and secondly, a gap equation for the superconducting state, which allows detailed calculations using phonon plus interlayer coupling, allows calculation of the large anisotropy of the gap, of the isotope effect, and of estimates of Tc and its dependence upon structure.
Optical leaky-wave antenna integrated in ring resonator

A leaky-wave antenna at optical frequencies is designed and integrated with a ring resonator at 1550 nm wavelength. The leaky wave is generated by using periodic perturbations in the integrated dielectric waveguide that excite the -1 spatial harmonic. The antenna consists of a dielectric waveguides with semiconductor corrugations, and it is compatible with CMOS fabrication technology. We show that integrating the leaky wave antenna in an optical ring resonator that is fed by directional couplers, we can improve the electronic control of the radiation through carrier injection into the semiconductor corrugations.
Three geometric applications of quandle homology

Abstract In this paper we describe three geometric applications of quandle homology. We show that it gives obstructions to tangle embeddings, provides the lower bound for the 4-move distance between links, and can be used in determining periodicity of links.
A statistical study of active regions 1967–1981

We have studied 15 years of active region data based on the Mount Wilson daily magnetograms in the interval 1967–1981. The analysis revealed the following: (1) The integral number of regions decreases exponentially with increasing region sizes, or N(A) = 4788 exp(-A/175) for the 15 years of data, where A is the area in square degrees and N(A) is the number of active regions with area ≥A. (2) The average area of active regions varies with the phase of the solar cycle. There are more larger regions during maximum than during minimum. (3) Regions in the north are 10% larger on average than those in the south during this interval. This coincides with a similar asymmetry in the total magnetic flux between the hemispheres. (4) Regions of all sizes and magnetic complexities show the same characteristic latitude variation with phase in the solar cycle. The largest regions, however, show a narrower latitude range.
Improving Turbine Component Efficiency

The thermal efficiency of a gas turbine engine depends on the cycle pressure and temperature ratio and on the aerodynamic efficiencies of the gas path components. Maintaining and/or improving structural integrity and aerodynamic efficiency in this high pressure, high temperature environment is the preeminent problem of the turbine designer. High gas temperatures require at least some of the metal structure to be cooled, yet cooling air is a loss to the cycle and its consumption must be kept to a minimum. Research into cooling techniques and boundary layer behavior on airfoils and endwalls and into test procedures for obtaining heat transfer data are providing some of the answers the designer needs. Increased operating-pressures generate increased mechanical stresses. Finite element analyses and automated design procedures are proving to be powerful aids to the designer. Improving aerodynamic efficiency requires careful control of the flow in three dimensions, particularly in low aspect ratio machines. The first practical computation method for three-dimensional, viscous, transonic flows became available in late 1977 and has made this one of the most exciting areas of turbine technology. Additional gains in aerodynamic efficiency can be realized by controlling leakages, especially those over the rotor tip, by accounting for the transient interactions between rotor and stator; and by careful control of discharged coolant flow. This paper briefly describes the turbine cooling research conducted by the Air Force Aero Propulsion Laboratory and describes more extensively the AFAPL programs in turbine aerodynamics, including applications of three-dimensional flow analysis.
Pruritus in patients treated with targeted cancer therapies: systematic review and meta-analysis

Background Pruritus has been anecdotally described in association with targeted cancer therapies. The risk of pruritus has not been systematically ascertained. Objective A systematic review and meta-analysis of the literature was conducted for axitinib, cetuximab, dasatinib, erlotinib, everolimus, gefitinib, imatinib, ipilimumab, lapatinib, nilotinib, panitumumab, pazopanib, rituximab, sorafenib, temsirolimus, tositumomab, vandetanib, and vemurafenib. Methods Databases from PubMed, Web of Science (January 1998 through July 2012), and American Society of Clinical Oncology abstracts (2004 through 2012) were searched. Incidence and relative risk of pruritus were calculated using random- or fixed-effects model. Results The incidences of all-grade and high-grade pruritus were 17.4% (95% confidence interval 16.0%-19.0%) and 1.4% (95% confidence interval 1.2%-1.6%), respectively. There was an increased risk of all-grade pruritus (relative risk 2.90 [95% confidence interval 1.76-4.77, P Limitations The reporting of pruritus may vary, resulting from concomitant medications, comorbidities, and underlying malignancies. We found a higher incidence of pruritus in patients with solid tumors, concordant with those targeted therapies with the highest pruritus incidences. Conclusion There is a significant risk of developing pruritus in patients receiving targeted therapies. To prevent suboptimal dosing and decreased quality of life, patients should be counseled and treated against this untoward symptom.
Evolutionary perspectives on salary dispersion within firms

In contrast with neoclassical economic models that assume that individuals hold preferences independently of others, there exist growing bodies of research demonstrating that preferences are often interdependent and based upon relative comparisons. This paper reviews research concerning salary dispersion within firms through the framework of four hypotheses that are generated by evolutionary perspectives. Contrary to some characterizations of evolutionary social science, this review presumes that there exist multiple evolutionary perspectives that have applicability to matters of practical importance. Basic findings include recognition of a strong evolutionarily-sensible preference for relatively high salary standings that is independent of absolute salary amounts. Synthetic findings include identification of research problems that future, directed studies can profitably address. For practical application, my review finds that evolved preferences appear more aligned with salary structures that are dispersed relatively evenly among co-workers when compared with tournament-style compensation patterns.
Relativized circuit complexity

Abstract We compare the measures of sequential time modelled using Turing machines and of parallel size modelled using Boolean circuits. This is done by constructing oracles which show certain relationships between complexity classes. An oracle B is shown for which Δ2P,B has 2n+o(n) size circuits relative to B. On the other hand, we give a C so that PC does not, for any k, have size nk circuits relative to C and yet NPC ≡ coNPC. These techniques can be combined to yield a D relative to which PD has 2n + o(n) size circuits but RD does not have size nk circuits for any k.
Lazy and speculative execution in computer systems

The distinction between lazy and eager (or strict) evaluation has been studied in programming languages since Algol 60's call by name, as a way to avoid unnecessary work and to deal gracefully with infinite structures such as streams. It is deeply integrated in some languages, notably Haskell, and can be simulated in many languages by wrapping a lazy expression in a lambda. Less well studied is the role of laziness, and its opposite, speculation, in computer systems, both hardware and software. A wide range of techniques can be understood as applications of these two ideas. Laziness is the idea behind:Redo logging for maintaining persistent state and replicated state machines: the log represents the current state, but it is evaluated only after a failure or to bring a replica online.Copy-on-write schemes for maintaining multiple versions of a large, slowly changing state, usually in a database or file system.Write buffers and writeback caches in memory and file systems, which are lazy about updating the main store.Relaxed memory models and eventual consistency replication schemes (which require weakening the spec).Clipping regions and expose events in graphics and window systems.Carry-save adders, which defer propagating carries until a clean result is needed."Infinity" and "Not a number" results of floating point operations.Futures (in programming) and out of order execution (in CPUs), which launch a computation but are lazy about consuming the result. Dataflow is a generalization."Formatting operators" in text editors, which apply properties such as "italic" to large regions of text by attaching a sequence of functions that compute the properties; the functions are not evaluated until the text needs to be displayed.Stream processing in database queries, Unix pipes, etc., which conceptually applies operators to unbounded sequences of data, but rearranges the computation when possible to apply a sequence of operators to each data item in turn. Speculation is the idea behind:Optimistic concurrency control in databases, and more recently in transactional memoryPrefetching in memory and file systems.Branch prediction, and speculative execution in general in modern CPUs.Data speculation, which works especially well when the data is cached but might be updated by a concurrent process. This is a form of optimistic concurrency control.Exponential backoff schemes for scheduling a resource, most notably in LANs such as WiFi or classical Ethernet.All forms of caching, which speculate that it's worth filling up some memory with data in the hope that it will be used again. In both cases it is usual to insist that the laziness or speculation is strictly a matter of scheduling that doesn't affect the result of a computation but only improves the performance. Sometimes, however, the spec is weakened, for example in eventual consistency. I will discuss many of these examples in detail and examine what they have in common, how they differ, and what factors govern the effectiveness of laziness and speculation in computer systems.
A General Expert System Design for Diagnostic Problem Solving

Existing expert systems have a high percentage agreement with experts in a particular field in many situations. However, in many ways their overall behavior is not like that of a human expert. These areas include the inability to give flexible, functional explanations of their reasoning processes, and the failure to degrade gracefully when dealing with problems at the periphery of their knowledge. These two important shortcomings can be improved when the right knowledge is available to the system. This paper presents an expert system design, called the integrated diagnostic model (IDM), that integrates two sources of knowledge, a shallow, reasoning-oriented, experiential knowledge base and a deep, functionally oriented, physical knowledge base. To demonstrate the IDM's usefulness in the problem area of diagnosis and repair, an implementation in the mechanical domain is described.
Symmetry-based photo-editing

In this paper, we demonstrate how to edit digital photos based on the understanding of high-level geometric knowledge imposed upon objects in the photos. This is achieved by the correct recovery of the 3-D shape and relationships of the objects, without explicitly performing full 3-D reconstruction. Symmetry is proposed as the central notion that unifies both conceptually and algorithmically all types of geometric regularities such as parallelism, orthogonality, and similarity. The methods are extremely simple, accurate, easy to implement, and they demonstrate the utility of applying scene knowledge to image understanding and editing.
Densities in free groups and $\mathbb{Z}^k$, Visible Points and Test Elements

In this article we relate two different densities. Let $F_k$ be the free group of finite rank $k \ge 2$ and let $\alpha$ be the abelianization map from $F_k$ onto $ \mathbb{Z}^k$. We prove that if $S \subseteq \mathbb{Z}^k$ is invariant under the natural action of $SL(k, \mathbb{Z})$ then the asymptotic density of $S$ in $\mathbb Z^k$ and the annular density of its full preimage $\alpha^{-1}(S)$ in $F_k$ are equal. This implies, in particular, that for every integer $t\ge 1$, the annular density of the set of elements in $F_k$ that map to $t$-th powers of primitive elements in $\mathbb{Z}^k$ is equal to $\frac{1}{t^k\zeta(k)}$, where $\zeta$ is the Riemann zeta-function. An element $g$ of a group $G$ is called a \emph{test element} if every endomorphism of $G$ which fixes $g$ is an automorphism of $G$. As an application of the result above we prove that the annular density of the set of all test elements in the free group $F(a,b)$ of rank two is $1-\frac{6}{\pi^2}$. Equivalently, this shows that the union of all proper retracts in $F(a,b)$ has annular density $\frac{6}{\pi^2}$. Thus being a test element in $F(a,b)$ is an ``intermediate property'' in the sense that the probability of being a test element is strictly between $0$ and $1$.
A Supersymmetric Stueckelberg U(1) extension of the MSSM

A Stueckelberg extension of the MSSM with only one abelian vector and one chiral superfield as an alternative to an abelian extension with Higgs scalars is presented. The bosonic sector contains a new gauge boson Z' which is a sharp resonance, and a new CP-even scalar, which combines with the MSSM Higgs bosons to produce three neutral CP-even massive states. The neutral fermionic sector has two additional fermions which mix with the four MSSM neutralinos to produce an extended 6 × 6 neutralino mass matrix. For the case when the LSP is composed mostly of the Stueckelberg fermions, the LSP of the MSSM will be unstable, which leads to exotic decays of sparticles with many leptons in final states. Prospects for supersymmetry searches and for dark matter are discussed.
The impact of regulation on firms’ ability to habitually meet or beat analysts’ expectations

Abstract Firms are pressured to meet or beat analysts’ expectations (MBE) to avoid being penalized by the market. Some firms sporadically MBE while other firms are able to consistently, or habitually, MBE. This study is an exploratory attempt to investigate how habitual MBE firms are different from firms that sporadically MBE, and whether regulation FD and the Sarbanes–Oxley Act have affected firms’ ability to habitually MBE in the post regulation periods. We find that habitual MBE firms are different than sporadic MBE firms, and that they use strategies less to MBE than sporadic MBE firms. Furthermore, it has become more difficult for firms to habitually MBE in the post-regulation periods.
Voting power apportionments

I propose apportioning the United States House of Representatives so as to equalize, to the extent possible, the voting power of the individual voter. Surprisingly such an apportionment falls squarely within the traditional apportionment paradigm and is, in a very precise sense, midway between the Hill method and the Webster method of apportionment.
Periodic modules over Gorenstein local rings

Abstract It is proved that the minimal free resolution of a module M over a Gorenstein local ring R is eventually periodic if, and only if, the class of M is torsion in a certain Z [ t ± 1 ] -module associated to R. This module, denoted J ( R ) , is the free Z [ t ± 1 ] -module on the isomorphism classes of finitely generated R-modules modulo relations reminiscent of those defining the Grothendieck group of R. The main result is a structure theorem for J ( R ) when R is a complete Gorenstein local ring; the link between periodicity and torsion stated above is a corollary.
Large-capacity neural nets for scene analysis

We consider the classification of multiple objects in a scene with distortion and clutter present. Our opinions on the role for neural nets (NNs) in this application and the different properties that NNs must have to address this problem are advanced. A hierarchical/inference approach is suggested using correlation NNs for low-level operations and new classifier NNs with higher-order decision surfaces for the final decision NNs. Our concern is NN capacity and performance (in noise). Our capacity guidelines advanced concern the number of neurons, use of analog neurons, Ho-Kashyap (HK) NNs, and two new NNs with higher-order decision surfaces. Our noise performance guidelines advanced concern the number of neuron layers, hidden-layer neuron encoding, and robust HK NNs.
Mass Segregation in the Globular Cluster NGC 6397

Our deep HST images of the center of the globular cluster NGC 6397 are almost devoid of faint stars, implying that these stars must be much less concentrated to the cluster center than the brighter stars. This difference is an expected consequence of energy exchanges through stellar encounters, which give higher velocities to lower mass stars and cause them to have a larger average distance from the cluster center. The amount of segregation that we observe is consistent with the predictions of a multimass model in dynamical equilibrium.
Abl Tyrosine Kinase Regulates Endocytosis of the Epidermal Growth Factor Receptor

Signal attenuation from ligand-activated epidermal growth factor receptor (EGFR) is mediated in part by receptor endocytosis and trafficking to the lysosomal degradative compartment. Uncoupling the activated EGFR from endocytosis and degradation has emerged as a mechanism for oncogenic activation of the EGFR. The Abl nonreceptor tyrosine kinase is activated by ligand-stimulated EGFR, but the role of Abl in EGFR signaling has not been defined. Here we uncovered a novel role for the activated Abl kinase in the regulation of EGFR endocytosis. We show that activated Abl impairs EGFR internalization. Moreover, we show that activated Abl phosphorylates the EGFR primarily on tyrosine 1173, and that mutation of this site to phenylalanine restores ligand-dependent endocytosis of the EGFR in the presence of activated Abl. Furthermore, we show that activated Abl allows the ligand-activated EGFR to escape Cbl-dependent down-regulation by inhibiting the accumulation of Cbl at the plasma membrane in response to epidermal growth factor stimulation and disrupting the formation of the EGFR·Cbl complex without affecting Cbl protein stability. These findings reveal a novel role for Abl in promoting increased cell-surface expression of the EGFR and suggest that Abl/EGFR signaling may cooperate in human tumors.
Experiments in the use of game technology for pre-visualization

This overview paper outlines the value of real-time 3D engines for pre-visualization. Pre-visualization is a standard tool during pre-production of many modern film productions. First, the parallels between the two increasingly digitized technologies are discussed. Second, the paper outlines the special needs and problems posed by pre-visualization. It argues that animation control and camera control are the two main areas that need to be addressed. Finally, it presents a range of experiments that provide different practical approaches to these two core questions and utilize available game technology. The approach of these tests was to keep the rendering real-time -- "liquid" -- as long as possible. This follows original machinima-like production pipelines. Ultimately, the here presented prototypes illustrate the value of real-time game engines for pre-visualization as well as still prevailing limitations.
Cell type–specific mRNA purification by translating ribosome affinity purification (TRAP)

Cellular diversity and architectural complexity create barriers to understanding the function of the mammalian CNS at a molecular level. To address this problem, we have recently developed a methodology that provides the ability to profile the entire translated mRNA complement of any genetically defined cell population. This methodology, which we termed translating ribosome affinity purification, or TRAP, combines cell type-specific transgene expression with affinity purification of translating ribosomes. TRAP can be used to study the cell type-specific mRNA profiles of any genetically defined cell type, and it has been used in organisms ranging from Drosophila melanogaster to mice and human cultured cells. Unlike other methodologies that rely on microdissection, cell panning or cell sorting, the TRAP methodology bypasses the need for tissue fixation or single-cell suspensions (and the potential artifacts that these treatments introduce) and reports on mRNAs in the entire cell body. This protocol provides a step-by-step guide to implement the TRAP methodology, which takes 2 d to complete once all materials are in hand.
Can corrosion and CRUD actually improve safety margins in LWRs

Abstract It is well known that boiling and quenching heat transfer depends strongly on the morphology and composition of the solid surface through which the heat transfer occurs. The relevant surface features are roughness, wettability (hydrophilicity), porosity, presence of cavities, size and shape of cavities, and thermo-physical properties of the surface material. Recent work at MIT has explored the separate effects of surface roughness, wettability and porosity on both Critical Heat Flux (CHF) and quenching heat transfer (Leidenfrost point temperature). Briefly, interconnected porosity within a hydrophilic matrix greatly enhances the CHF (by as much as ∼60%) and the Leidenfrost temperature (by as much as ∼150 °C). Surprisingly, surface roughness has a comparably minor effect on both CHF and quenching. There are opportunities to exploit in Light Water Reactor (LWR) nuclear plants, where CHF and quenching determine the thermal margins in during loss-of-flow and loss-of-coolant accidents, respectively, and the surface of the fuel naturally develops porous hydrophilic layers because of CRUD deposition and corrosion. This paper reviews the MIT experimental database generated using engineered surfaces with carefully-controlled characteristics, and discuss its applications to LWR safety, both design-basis and beyond-design-basis accidents.
Estimation of interval anisotropic attenuation from reflection data

Knowledge of interval attenuation can be highly beneficial in reservoir characterization and lithology discrimination. We combine the spectral-ratio method with velocity-independent layer stripping to develop a technique for the estimation of the interval attenuation coefficient from reflection seismic data. The layer-stripping procedure is based on identifying the reflections from the top and bottom of the target layer that share the same ray segments in the overburden. The algorithm is designed for heterogeneous, arbitrarily anisotropic target layers, but the overburden is assumed to be laterally homogeneous with a horizontal symmetry plane. Although no velocity information about the overburden is needed, interpretation of the computed anisotropic attenuation coefficient involves the phase angle in the target layer. Tests on synthetic P-wave data from layered transversely isotropic and orthorhombic media confirm the high accuracy of 2D and 3D versions of the algorithm. We also demonstrate that the interval attenuation estimates are independent of the inhomogeneity angle of the incident and reflected waves.
Thermodynamics and Universality for Mean Field Quantum Spin Glasses

We study aspects of the thermodynamics of quantum versions of spin glasses. By means of the Lie-Trotter formula for exponential sums of operators, we adapt methods used to analyze classical spin glass models to answer analogous questions about quantum models.
Structured organization of clinical data bases

The health care delivery system is under strong pressures from several sides. Many of these pressures derive from the demand for a more comprehensive range of health services and from the increased complexity of disease and treatment patterns. Since medical science has provided tools to manage many of the once common diseases, it now has to cope with problems of less well understood origin and course. The practicing physician is faced with an information explosion of major dimensions and a gap between scientific knowledge in a basic form and its practical application at the bedside.
Application of enzymatic methods to the synthesis of 5-substituted-2-furanones

Abstract Porcine pancreatic lipase (PPL) and baker's yeast (BY) have been successfully used in the synthesis of optically active 5-substituted-2-furanones.
Run-time principals in information-flow type systems

Information-flow type systems are a promising approach for enforcing strong end-to-end confidentiality and integrity policies. Such policies, however, are usually specified in terms of static information—data is labeled high or low security at compile time. In practice, the confidentiality of data may depend on information available only while the system is running. This article studies language support for run-time principals, a mechanism for specifying security policies that depend on which principals interact with the system. We establish the basic property of noninterference for programs written in such language, and use run-time principals for specifying run-time authority in downgrading mechanisms such as declassification. In addition to allowing more expressive security policies, run-time principals enable the integration of language-based security mechanisms with other existing approaches such as Java stack inspection and public key infrastructures. We sketch an implementation of run-time principals via public keys such that principal delegation is verified by certificate chains.
Aberration and the Fundamental Speed of Gravity in the Jovian Deflection Experiment

We describe our explicit Lorentz-invariant solution of the Einstein and null geodesic equations for the deflection experiment of 2002 September 8 when a massive moving body, Jupiter, passed within 3.7’ of a line-of-sight to a distant quasar. We develop a general relativistic framework which shows that our measurement of the retarded position of a moving light-ray deflecting body (Jupiter) by making use of the gravitational time delay of quasar’s radio wave is equivalent to comparison of the relativistic laws of the Lorentz transformation for gravity and light. Because, according to Einstein, the Lorentz transformation of gravity field variables must depend on a fundamental speed c, its measurement through the retarded position of Jupiter in the gravitational time delay allows us to study the causal nature of gravity and to set an upper limit on the speed of propagation of gravity in the near zone of the solar system as contrasted to the speed of the radio waves. In particular, the v/c term beyond of the standard Einstein’s deflection, which we measured to 20% accuracy, is associated with the aberration of the null direction of the gravity force (“aberration of gravity”) caused by the Lorentz transformation of the Christoffel symbols from the static frame of Jupiter to the moving frame of observer. General relativistic formulation of the experiment identifies the aberration of gravity with the retardation of gravity because the speed of gravitational waves in Einstein’s theory is equal to the speed of propagation of the gravity force. We discuss the misconceptions which have inhibited the acceptance of this interpretation of the experiment. We also comment on other interpretations of this experiment by Asada, Will, Samuel, Pascual–Sanchez, and Carlip and show that their “speed of light” interpretations confuse the Lorentz transformation for gravity with that for light, and the fundamental speed of gravity with the physical speed of light from the quasar. For this reason, the “speed of light” interpretations are not entirely consistent with a retarded Lienard–Wiechert solution of the Einstein equations, and do not properly incorporate how the phase of the radio waves from the quasar is perturbed by the retarded gravitational field of Jupiter. Although all of the formulations predict the same deflection to the order of v/c, our formulation shows that the underlying cause of this deflection term is associated with the aberration of gravity and not of light, and that the interpretations predict different deflections at higher orders of v/c beyond the Shapiro delay, thus, making their measurement highly desirable for deeper testing of general relativity in future astrometric experiments like Gaia, SIM, and SKA.
Toward the Total Synthesis of Bryostatin 11: Stereoselective Construction of the C13-Exocyclic Enoate in the C1–C16 Fragment

Abstract We have utilized a spiroketal template in an approach to the C1–C16 fragment of bryostatin. The stereoselective construction of an exocyclic enoate at C13 and insertion of a vinyl group on C15 were accomplished by using Peterson–Yamamoto olefination and copper-catalyzed addition of vinyl magnesium bromide, respectively.
Acceptability-oriented computing

We discuss a new approach to the construction of software systems. Instead of attempting to build a system that is as free of errors as possible, the designer instead identifies key properties that the execution must satisfy to be acceptable to its users. Together, these properties define the acceptability envelope of the system: the region that it must stay within to remain acceptable. The developer then augments the system with a layered set of components, each of which enforces one of the acceptability properties. The potential advantages of this approach include more flexible, resilient systems that recover from errors and behave acceptably across a wide range of operating environments, an appropriately prioritized investment of engineering resources, and the ability to productively incorporate unreliable components into the final software system.
Sol–Gel Coating of Powders for Processing Electronic Ceramics

A new technique (sol-gel coating of powders) was utilized to process electronic ceramics such as Sb-doped SnO2 and positive-temperature-coefficient-of-resistance (PTCR) BaTiO3 thermistors. Sol-gel coatings resulted in the densification via a liquid phase of Sb-doped SnO2 powders. PTCR thermistors were developed from BaTiO3 powders coated by a sol-gel composition containing dopants (Y), counterdopants (Mn, F), and additives (Si) with uniform microstructures and improved properties. Incorporation of F via the sol-gel coating increased the reliability of PTCR devices, making them less sensitive to reducing environments. This process may be extended to the processing of other electronic materials.
The Mass Transfer Analogy to Heat Transfer in Fluids With Temperature-Dependent Properties

The analogy between heat transfer in a single-component fluid and isothermal mass transfer of a two-component fluid without chemical reaction is presented. The analogy is well established and frequently used for fluids with constant properties. However, in various applications such as in the cooling of hot components in gas turbines, the temperature varies widely, causing significant fluid property variations. The present paper reviews the constant-property situation and considers in detail the conditions necessary to ensure similarity of the two transport processes with temperature and concentration-dependent fluid properties. An application of the variable property analogy to mass transfer in binary mixtures is presented along with specific recommendations for the CO2 –air and Freon-air systems. It is demonstrated that the essential similarity conditions of the analogy are very well fulfilled for film cooling, total coverage film cooling, and impingement cooling when the heat (mass) flux into the wall in the transport process is zero. The heat/mass transfer analogy can, therefore, be used with confidence for these processes.
Type I Planet Migration in Nearly Laminar Disks

We describe two-dimensional hydrodynamic simulations of the migration of low-mass planets ( 30 M⊕) in nearly laminar disks (viscosity parameter α< 10 −3 ) over timescales of several thousand orbit periods. We consider disk masses of 1, 2, and 5 times the minimum mass solar nebula, disk thickness parameters of H/r = 0.035 and 0.05, and a variety of α values and planet masses. Disk self-gravity is fully included. Previous analytic work has suggested that Type I planet migration can be halted in disks of sufficiently low turbulent viscosity, for α ∼ 10 −4 . The halting is due to a feedback effect of breaking density waves that results in a slight mass redistribution and consequently an increased outward torque contribution. The simulations confirm the existence of a critical mass (Mcr ∼ 10M⊕) beyond which migration halts in nearly laminar disks. For α 10 −3 , density feedback effects are washed out and Type I migration persists. The critical masses are in good agreement with the analytic model of Rafikov. In addition, for α 10 −4 steep density gradients produce a vortex instability, resulting in a small time-varying eccentricity in the planet’s orbit and a slight outward migration. Migration in nearly laminar disks may be sufficiently slow to reconcile the timescales of migration theory with those of giant planet formation in the core accretion model.
Agents in real-time collaborative systems

Desktop conferencing systems, providing voice- or video-conferencing with some form of data sharing, have become increasingly popular. Unlike asynchronous collaborative systems such as email, little attention has been devoted to the place of agents in such real-time systems. This paper examines some of the ways in which agents can be used to support such apparently simple tasks as the setting up and answering of calls. Three agent categories, locators, routers and responders, are defined and some simple examples discussed. Several ways in which such agents can collaborate, providing the basis of an intelligent network, are identified.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Diffraction anomalous fine structure: a new technique for probing local atomic environment

Diffraction anomalous fine structure (DAFS) is the fine structure in the intensity of an X-ray diffraction peak in the vicinity of an absorption edge. DAFS is measured by monitoring the intensity of a diffraction peak as a function of the incident X-ray energy as it is scanned through an absorption edge. It combines the short range structural sensitivity of X- ray absorption spectroscopy with the long range periodicity of X-ray diffraction, and can provide structural information which is not available from these techniques alone, or in combination. We present a methodology which allows extraction of a specific X-ray absorbance spectrum from the DAFS spectrum, and illustrate it for KMnO4. We also demonstrate the ability of DAFS to separate the contributions to the X-ray absorption spectrum of the tetrahedral and octahedral cobalt sites in the spinel Co3O4
Nickel-Catalyzed Addition of Methylmagnesium Bromide to Alkynylsilanes. Stereospecific Synthesis of Tetrasubstituted Alkenes

Methylmagnesium bromide adds to trimethylsilyloctyne (1) in the presence of 10 mol% 1:0.67 nickel acetylacetonate-trimethylaluminum to give a 9:1 mixture of alkenyl Grignard reagents 2a and 3a. This mixture reacts with water, deuterium oxide, formaldehyde, acetaldehyde, carbon dioxide, iodine, vinyl bromide or allyl bromide to give the expected products 2, 3b to 2, 3j. Nickel catalyzed carbometallation of 4 with MeMgBr followed by quenching with formaldehyde and desilylation gives trans, trans-farnesol (5c). Nickel catalyzed addition of MeMgBr to 6a and 6b proceeds analogously, except that initially formed alkenyl Grignard reagents 7a and 7b isomerize completely to 8a and 8b which are stabilized by chelation. This carbometallation reaction allows the synthesis of both isomers of an allylic alcohol, such as 12 and 13, from a common intermediate 2a.
Simulation-based optimization over discrete sets with noisy constraints

This article considers a constrained optimization problem over a discrete set where noise-corrupted observations of the objective and constraints are available. The problem is challenging because the feasibility of a solution cannot be known for certain, due to the noisy measurements of the constraints. To tackle this issue, a method is proposed that converts constrained optimization into the unconstrained optimization problem of finding a saddle point of the Lagrangian. The method applies stochastic approximation to the Lagrangian in search of the saddle point. The proposed method is shown to converge, under suitable conditions, to the optimal solution almost surely as the number of iterations grows. The effectiveness of the proposed method is demonstrated numerically in three settings: (i) inventory control in a periodic review system; (ii) staffing in a call center; and (iii) staffing in an emergency room.
Accuracy of the Burnett equations for hypersonic real gas flows

Burnett solutions for the structure of normal shock waves for Mach numbers ranging from 1.1 to 50 have been obtained by using the time-dependent equation set in conjunction with modern computational fluid dynamic techniques. The current work seeks to provide corrected and improved high-resolution direct simulation Monte Carlo (DSMC) results for hypersonic shocks in monatomic gases. These DSMC results will serve as a reliable test base for assessing the accuracy of various continuum equations more advanced than Navier-Stokes, such as the Burnett equations. The main conclusion of Fisko and Chapman (1988) that the Burnett equations are more accurate than the Navier-Stokes equations for all gases and at all Mach numbers in matching DSMC shock wave results is reassesed by comparing the improved and corrected DSMC results with continuum Burnett results. Various Burnett results for shocks in a diatomic gas, nitrogen, which include improvements to the work of Lumpkin and Chapman (1989) are presented. It is concluded that the Burnett equations represent a significant improvement over Navier-Stokes equations for flows exhibiting translational nonequilibrium.
Molecular Self-Healing Processes in Polymers

A critical review of self-healing processes in polymers and composites based on polymeric matrices is presented. Two self-healing processes are analyzed, one “operating” within micron range and the other at molecular scale. Preliminary data on the molecular self-healing process in living polymers, as obtained by electron spin resonance are discussed. The possibility to develop a multi-scale self-healing material is suggested.
Modeling intra-class variation for nonideal iris recognition

Intra-class variation is fundamental to the FNMR performance of iris recognition systems. In this paper, we perform a systematic study of modeling intra-class variation for nonideal iris images captured under less-controlled environments. We present global geometric calibration techniques for compensating distortion associated with off-angle acquisition and local geometric calibration techniques for compensating distortion due to inaccurate segmentation or pupil dilation. Geometric calibration facilitates both the localization and recognition of iris and more importantly, it offers a new approach of trading FNMR with FMR. We use experimental results to demonstrate the effectiveness of the proposed calibration techniques on both ideal and non-ideal iris databases.
Radio scintillation of gamma-ray-burst afterglows

Stars twinkle to the eye through atmospheric turbulence, but planets, because of their larger angular size, do not. Similarly, scintillation due to the local interstellar medium will modulate the radio flux of gamma-ray-burst afterglows and may permit indirect measurements of their angular sizes. The amplitude of refractive scintillation is of order ten percent at ten gigahertz unless the source size is much larger than the expected size, of order microarcseconds. Diffractive scintillation is marginally possible, depending sensitively on the source size, observing frequency, and scattering measure of the interstellar medium.
Large scale simulations of two-species annihilation, A+B→0, with drift

Abstract We present results of computer simulations of the diffusion-limited reaction process A + B →0, on the line, under extreme drift conditions, for lattices of up to 2 27 sites, and where the process proceeds to completion (no particles left). These enormous simulations are made possible by the renormalized reaction-cell method (RRC). Our results allow us to resolve an existing controversy about the rate of growth of domain sizes, and about corrections to scaling of the concentration decay.