cssi/SciSciGPT-SciSciNet huggingface dataset:
Bounds on Eigenvalues of a Spatial Correlation Matrix

It is critical to understand the properties of spatial correlation matrices in massive multiple-input-multiple-output (MIMO) systems. We derive new bounds on the extreme eigenvalues of a spatial correlation matrix that is characterized by the exponential model in this paper. The new upper bound on the maximum eigenvalue is tighter than the previously known bound. Moreover, numerical studies show that our new lower bound on the maximum eigenvalue is close to the true maximum eigenvalue in most cases. We also derive an upper bound on the minimum eigenvalue that is also tight. These bounds can be exploited to analyze many wireless communication scenarios including uniform planar arrays, which are expected to be widely used for massive MIMO systems.
WDVV and DZM

Abstract We show how the Witten-Dijkgraaf-Verlinde-Verlinde (WDVV) equations and the Darboux-Zakharov-Manakov (DZM) system can be characterized via a background family of functions. Connections to the Hirota bilinear identity are indicated.
Reconstructive breast surgery following mastectomy and adjunctive radiation therapy

With modern radiation, surgical therapy, and surgical reconstructive techniques, it is now possible to give adequate treatment for breast cancer and to reconstruct the breast as well, using a silicone implant prosthesis. Twelve mastectomies and reconstructions were performed on 8 patients. Seven of these had pre- or postoperative irradiation to one breast region, and 1 patient received irradiation to both breast areas. The clinical staging of patients with combined irradiation and surgery was Stage I—3 cases; Stage II—4 cases; and Stage III—1 case. Primary surgical procedures consisted of modified radical mastectomy for ten breast lesions and simple mastectomy for two others. Megavoltage radiotherapy was administered with a CO-60 Unit. Pre-operative irradiation of 4000 rads to the breast, chest wall, and regional lymphatics was given to 3 patients. Postoperative radiation therapy of 5000 rads to the chest wall and 4400–5000 rads to the regional lymphatics was given to 5 other patients, one of whom received bilateral irradiation. Adjunctive chemotherapy was employed in 5 patients with interruption during the period of implant surgery. Reconstructive surgery was performed 5 months to 14 months after irradiation in 7 patients and 5 1/2 years later in one patient. The procedure was a single stage operation with placement of a silicone prosthesis under the pectoralis muscle. No significant morbidity was encountered from radiotherapy, chemotherapy, or from the surgical procedures. Healing of surgical wounds after implantation was uncomplicated. Cosmetic results have been good. All patients are alive and well, 8 months to 6 1/2 years postirradiation and three months to three years post-breast reconstruction. Results to date have been most gratifying.
Development of embedded sensor models in composite laminates for structural health monitoring

A framework is developed to study the transient analysis of composite laminated plates with embedded discrete and continuous sensors in the presence of delaminations. The computational modeling involves development of a finite element scheme using an improved layerwise laminate theory to model laminates of arbitrary thickness. Parametric studies are conducted using laminated plates with both embedded sensors and continuous sensor architecture. The response of the plates under both low-frequency vibration and high-frequency acoustic emission are investigated. The effects on plate displacement and sensor outputs due to delaminations are studied. The scattering of the acoustic emission caused by the presence of delaminations is also investigated. It is expected that the developed model would be a useful tool in simulation studies aimed at characterizing the presence of delaminations in composite laminated structures.
Families as active monitors of firm performance

Abstract The role of owner-family members as internal monitors of firm performance has been largely neglected in family business studies so far. While family management of firms does not lead to clear performance improvements, accounting research has shown that families are better monitors. In this article we combine these findings and hypothesize that family monitoring leads to better firm performance. We test that hypothesis on a dataset of 386 German corporations as well as distinct subsamples for family businesses and SMEs. Using simultaneous quantile regressions we find consistent proof for our hypothesis over different quantiles of firm performance. We suspect family monitoring to be the missing link in the ownership, control and performance debate on family firms.
Stable Algebras of Entire Functions

. Suppose that h and g belong to the algebra B generated by the rational functions and an entire function f of finite order on C" and that h/g has algebraic polar variety. We show that either h/g 6 B or f = q i e P + q 2 , where p is a polynomial and q i , q 2 are rational functions. In the latter case, h/g belongs to the algebra generated by the rational functions, e P and e - P . The stability property is related to the problem of algebraic dependence of entire functions over the ring of polynomials. The case of algebraic dependence over C of two entire or meromorphic functions on C" is completely resolved in this paper.
A natural smooth compactification of the space of elliptic curves in projective space

The space of smooth genus-0 curves in projective space has a natural smooth compactification: the moduli space of stable maps, which may be seen as the generalization of the classical space of complete conics. In arbitrary genus, no such natural smooth model is expected, as the space satisfies “Murphy’s Law”. In genus 1, however, the situation remains beautiful. We give a natural smooth compactification of the space of elliptic curves in projective space, and describe some of its properties. This space is a blowup of the space of stable maps. It can be interpreted as a result of blowing up the most singular locus first, then the next most singular, and so on, but with a twist—these loci are often entire components of the moduli space. We give a number of applications in enumerative geometry and Gromov-Witten theory. For example, this space is used by the second author to prove physicists’ predictions for genus-1 Gromov-Witten invariants of a quintic threefold. The proof that this construction indeed gives a desingularization will appear in a
ALFALFA in the Leo Region: Looking for Missing Satellites in HI

The location of two nearby galaxy groups within ~20 Mpc in the Leo region allows for a detailed study of low-mass galaxies. A catalog of HI line detections in Leo (9h36m < RA <11h36m, +8deg < dec < +16deg) has been made from the blind HI survey ALFALFA. More sensitive single-pixel Arecibo observations targeted Leo dwarf candidates noted optically by Karachentsev et al 2004 (K04) to determine group members and allow for a comparison of HI and optically-selected samples. This presentation highlights the differences between the two samples and the significant contribution blind HI surveys can make to the missing satellites problem.
The role of DNA flow cytometry in borderline malignant ovarian tumors

Background The role of flow cytometric DNA analysis in predicting prognosis of patients with borderline malignant ovarian tumors has been controversial. Methods Fifty cases of patients with borderline malignant ovarian tumors were analyzed by histology and by flow cytometry on paraffin embedded tissue. Multiple tissue blocks and serial sections were analyzed for each tumor. The results of DNA analysis were correlated to clinicopathologic data. Results DNA aneuploidy was demonstrable in 4 cases (8%) when the most atypical section was analyzed. The overall rate of aneuploidy was 14% if additional blocks and serial sections were studied. Two patients died from tumor. One of the two patients had an initial diagnosis of Stage IIc mucinous borderline tumor with DNA indices (DI) of 1.12, 1.42, and 2.04. She had a recurrence in the contralateral ovary 1 year later (DI = 1.83), and a second frankly malignant recurrence diffusely in peritoneum (DI = 1.89). The other patient had an initial diagnosis of Stage IIIc mucinous borderline ovarian tumor with pseudomyxoma peritonei. DNA diploidy was obtained in all of the samples from the primary tumor. An aneuploid peak (DI = 1.28) was demonstrated in only one serial section of the peritoneal implants. Of the other 5 patients who had aneuploid histograms but were disease-free, the DNA indices were 1.35, 1.14/1.18, 1.15, 1.20, and 1.31 and were demonstrable only in either 1 or 2 of the blocks or unproven on serial sections. All patients with diploid-peridiploid tumors were alive and disease free. Conclusions Reproducible DNA aneuploidy of high DI may be predicting a poor outcome, whereas the significance of inconsistently reproducible aneuploidy of low DI remains to be determined. Further studies of prospective DNA analysis with adequate sampling are necessary to define the role of flow cytometry in patients with borderline malignant ovarian tumors.
Risk versus Demographics in Subprime Mortgage Lending: Evidence from Three Connecticut Cities

This paper analyzes patterns in subprime residential mortgage lending using 2006 Home Mortgage Act Disclosure data for the cities of Bridgeport, New Haven and Waterbury, Connecticut. The analysis applies models presented in earlier research and has the objective of assessing the relative importance of demographic versus risk factors in subprime mortgage lending decisions. Regression equations are estimated for census tracts and individual borrowers and include demographic variables and property risk measures. The results find race and ethnicity to be significant determinants of subprime lending in the borrower equations that include the full set of risk measures. Neighborhood educational levels are found to have an inverse and often significant association with subprime mortgage loans. Property risk measures present mixed results regarding their significance in subprime lending, suggesting that risk may have played less of a role in loan originations in 2006 than it did in earlier studies.
Lifshitz black holes in higher spin gravity

We study asymptotically Lifshitz solutions to three dimensional higher spin gravity in the SL(3;R) SL(3;R) Chern-Simons formulation. We begin by specifying the most general connections satisfying Lifshitz boundary conditions, and we verify that their algebra of symmetries contains a Lifshitz sub-algebra. We then exhibit connections that can be viewed as higher spin Lifshitz black holes. We show that when suitable holonomy conditions are imposed, these black holes obey sensible thermodynamics and possess a gauge in which the corresponding metric exhibits a regular horizon.
Many objective robust decision making for complex environmental systems undergoing change

This paper introduces many objective robust decision making (MORDM). MORDM combines concepts and methods from many objective evolutionary optimization and robust decision making (RDM), along with extensive use of interactive visual analytics, to facilitate the management of complex environmental systems. Many objective evolutionary search is used to generate alternatives for complex planning problems, enabling the discovery of the key tradeoffs among planning objectives. RDM then determines the robustness of planning alternatives to deeply uncertain future conditions and facilitates decision makers' selection of promising candidate solutions. MORDM tests each solution under the ensemble of future extreme states of the world (SOW). Interactive visual analytics are used to explore whether solutions of interest are robust to a wide range of plausible future conditions (i.e., assessment of their Pareto satisficing behavior in alternative SOW). Scenario discovery methods that use statistical data mining algorithms are then used to identify what assumptions and system conditions strongly influence the cost-effectiveness, efficiency, and reliability of the robust alternatives. The framework is demonstrated using a case study that examines a single city's water supply in the Lower Rio Grande Valley (LRGV) in Texas, USA. Results suggest that including robustness as a decision criterion can dramatically change the formulation of complex environmental management problems as well as the negotiated selection of candidate alternatives to implement. MORDM also allows decision makers to characterize the most important vulnerabilities for their systems, which should be the focus of ex post monitoring and identification of triggers for adaptive management.
Pricing online subscription services under competition

In recent times, rapid advances in the field of information technology have enabled firms selling information products (for example, in the form of a CD) to provide subscription services using remote servers. Making the product versus service decision involves a trade-off. Online subscription offerings are perceived to be of lower quality because of data security and network reliability issues but can reduce or even eliminate the credible commitment (of prices) problem typically faced by firms selling durable products. We model an infinite horizon game between two symmetric firms that choose the design architecture, that is, product or service (and consequent contracting scheme: selling or subscription) and then set prices to optimize profits. The perceived quality loss enables firms to differentiate based on design architecture/contracting scheme and make positive profits. Further, the firm that sells a product makes higher profit than the firm that offers a subscription service. However, as the discount factor increases, the presence of a seller leads to a credible commitment problem for both firms leading to a reduction in prices. The results offer an explanation for the persistence of firms selling products rather than services. Further, a firm offering a subscription service may be subject to price pressure due to the price commitment issues of a competing seller. We also extend our insights to other settings: one involving asymmetric firms and the other involving different discount rates for product quality and producer/consumer surplus.
Foreclosure of Securitized Commercial Mortgages—A Model of the Special Servicer

The decision to foreclose on a CMBS mortgage is made by the special servicer. A mortgage loan is in special servicing when it is either delinquent or in a state of imminent default. A special servicer should represent the interests of the underlying CMBS bondholders by returning the highest possible value to the investors. In this paper, we show that a special servicer’s compensation structure results in an incentive for her to extend a loan beyond the time desired by its bondholders. We develop a model and demonstrate how compensation incentives interact and influence a special servicer’s foreclosure decisions. Our model takes into consideration the dynamic nature of such a decision by viewing is as a dynamic programming problem whereby foreclosure represents a discrete terminal state of an optimal stopping problem. This model thus captures the trade-off between continuation of a loan and termination and we use this model to determine how the stopping rule changes under various compensation structures.
The Marinopyrroles, Antibiotics of an Unprecedented Structure Class from a Marine Streptomyces sp.

Cultivation of an obligate marine Streptomyces strain has furnished the marinopyrroles A and B, densely halogenated, axially chiral metabolites that contain an uncommon bispyrrole structure. X-ray analysis of marinopyrrole B showed that the natural product exists as an atropo-enantiomer with the M-configuration. Though configurationally stable at room temperature, M-(−)-marinopyrrole A can be racemized at elevated temperatures to yield the non-natural P-(+)-atropo-enantiomer. The marinopyrroles possess potent antibiotic activities against methicillin-resistant Staphylococcus aureus.
Equilibrium oxygen fugacity in titanium ferrites

The subsolidus equilibrium oxygen fugacities for the boundaries of the Fe3O4Fe2TiO4 stability field above 1000°C have been calculated from available data. A Frenkel point defect equilibrium model is described, which uniquely determines the single phase intrinsic oxygen fugacity, as a function of temperature, Ti content, and metal-oxygen stoichiometry. Gleichgewichts-Sauerstoff-Fugazitat in Titanferriten Die Subsolidus-Gleichgewichts-Sauerstoff-Fugazitaten fur die Grenzen des Fe3O4Fe2TiO4-Stabilitatsgebietes uber 1000°C sind aus verfugbaren Daten berechnet worden. Ein Frenkel-Fehlstellen-Gleichgewichts-Modell wird beschrieben, das einheitlich die Sauerstoff-Fugazitat der Reinen Einzelphasen als Funktion von Temperatur, Titangehalt und Metall-Sauerstoff-Stochiometrie bestimmt.
Action-angle variables for the Gel'fand-Dikii flows

Using the scattering transform fornth order linear scalar operators, the Poisson bracket found by Gel'fand and Dikii, which generalizes the Gardner Poisson bracket for the KdV hierarchy, is computed on the scattering side. Action-angle variables are then constructed. Using this, complete integrability is demonstrated in the strong sense. Real action-angle variables are constructed in the self-adjoint case.
Development and Testing of a Single Frequency Terahertz Imaging System for Breast Cancer Detection

The ability to discern malignant from benign tissue in excised human breast specimens in Breast Conservation Surgery (BCS) was evaluated using single frequency terahertz radiation. Terahertz (THz) images of the specimens in reflection mode were obtained by employing a gas laser source and mechanical scanning. The images were correlated with optical histological micrographs of the same specimens, and a mean discrimination of 73% was found for five out of six samples using Receiver Operating Characteristic (ROC) analysis. The system design and characterization is discussed in detail. The initial results are encouraging but further development of the technology and clinical evaluation is needed to evaluate its feasibility in the clinical environment.
Can you play a fair game of craps with a loaded pair of dice

The parts-to-totals map sends the distributions of a set of independent random variables on a finite set of probability spaces to the total distribution of their sum on the product space. We study,...
Asymptotic stability of systems with saturation constraints

In the present paper the authors establish new sufficient conditions for the global asymptotic stability of linear systems operating on the unit hypercube in R/sup n/ and of linear systems with partial state saturation constraints. They also determine a set of necessary and sufficient conditions for the global asymptotic stability of second order linear systems with saturation constraints on both states using the above results. Systems of the type considered herein are widely used in several areas of applications, including control systems, signal processing, and artificial neural networks.
Messenger RNA 3′ End Formation in Plants

Messenger RNA 3' end formation is an integral step in the process that gives rise to mature, translated messenger RNAs in eukaryotes. With this step, a pre-messenger RNA is processed and polyadenylated, giving rise to a mature mRNA bearing the characteristic poly(A) tract. The poly(A) tract is a fundamental feature of mRNAs, participating in the process of translation initiation and being the focus of control mechanisms that define the lifetime of mRNAs. Thus messenger RNA 3' end formation impacts two steps in mRNA biogenesis and function. Moreover, mRNA 3' end formation is something of a bridge that integrates numerous other steps in mRNA biogenesis and function. While the process is essential for the expression of most genes, it is also one that is subject to various forms of regulation, such that both quantitative and qualitative aspects of gene expression may be modulated via the polyadenylation complex. In this review, the current status of understanding of mRNA 3' end formation in plants is discussed. In particular, the nature of mRNA 3' ends in plants is reviewed, as are recent studies that are beginning to yield insight into the functioning and regulation of plant polyadenylation factor subunits.
A search for stable strange quark matter nuggets in helium

Abstract A search for stable strange quark nuggets has been conducted in helium and argon using a high sensitivity mass spectrometer. The search was guided by a mass formula for strange quark nuggets which suggested that stable strange helium might exist at a mass around 65 u. The chemical similarity of such “strangelets” to noble gas atoms and the gravitational unboundedness of normal helium result in a large enhancement in the sensitivity of such a search. An abundance limit of no more than 2 · 10−11 strangelets per normal nucleus is imposed by our search over a mass region from 42 to 82 u, with much more stringent limits at most (non-integer) masses.
Symbolic model checking for sequential circuit verification

The temporal logic model checking algorithm of Clarke, Emerson, and Sistla (1986) is modified to represent state graphs using binary decision diagrams (BDD's) and partitioned transition relations. Because this representation captures some of the regularity in the state space of circuits with data path logic, we are able to verify circuits with an extremely large number of states. We demonstrate this new technique on a synchronous pipelined design with approximately 5/spl times/10/sup 120/ states. Our model checking algorithm handles full CTL with fairness constraints. Consequently, we are able to express a number of important liveness and fairness properties, which would otherwise not be expressible in CTL. We give empirical results on the performance of the algorithm applied to both synchronous and asynchronous circuits with data path logic. >
Ultrasonic velocities of opaline rocks undergoing silica diagenesis

Experimental results of laboratory measurements at ultrasonic frequencies on dry opaline rocks are documented from the Monterey Formation, a siliceous unit in the San Joaquin basin. In these samples the silica is primarily biogenic opal-A in origin, but progressively alters to opal-CT and then quartz with depth. The diagenetic transitions are accompanied by a marked porosity reduction. Compressional and shear wave velocities were measured on core plugs at effective reservoir pressure. Experimental results on samples from the opal-A/opal-CT transition and the opal-CT/quartz transition show very little pressure-dependence of elasticwave velocities. When their elastic moduli are normalized by those of the solid phase, the moduli-porosity trend is very close to that of chalk and, in the lower-porosity domain, of some clean sandstones.
Optimum Design of Space Storable Gas/Liquid Coaxial Injectors

Results from an experimental program are presented whose objective was to establish performance and chamber compatibility design criteria for circular coaxial injector concepts for application with the space storable gas/liquid propellant combination FLOX (82.6% F2, 17.4% O2)/CH4(g) at high pressure. The primary goal of the program was to obtain high characteristic velocity efficiency (77^ > 99%) in conjunction with acceptable injector/chamber compatilibity. Subscale (single-element) cold-flow and hot-fire experiments were employed to establish design criteria for a 3000 Ibf (sea level) engine operating at 500 psia. The subscale experiments characterized both high performance "core" elements and "peripheral" elements with enhanced injector/chamber compatibility. The full-scale injector which evolved from the study demonstrated a performance level of 99 % of the theoretical shifting characteristic exhaust velocity with low chamber heat flux levels. At the design condition (Pc = 500 psia), measured heat flux levels were approximately 2 to 3 Btu/in.2-sec in the graphite cylindrical chamber; the heat flux levels were predicted by initial program efforts with subscale, low-cost, single-element hardware. Full-scale injector durability was demonstrated during a 44-sec firing; additionally, dynamic stability was demonstrated by a 15-msec recovery to a 1100 psi chamber overpressure.
Radiative Transitions in Charmonium

The form factors for the radiative transitions between charmonium mesons are investigated. We employ an anisotropic lattice using a Wilson gauge action, and domain-wall fermion action. We extrapolate the form factors to Q2 = 0, corresponding to a real photon, using quark-model-inspired functions. Finally, comparison is made with photocouplings extracted from the measured radiative widths, where known. Our preliminary results find photocouplings commensurate with these experimentally extracted values.
Vehicle fuel-efficiency choices, emission externalities, and urban sprawl

This paper shows that a city where both a congestion externality and an externality from greenhouse gas emissions are corrected by efficient policies is more compact than the laissez-faire equilibrium city. Motivated by recent empirical studies showing a positive relationship between population density and vehicle fuel-efficiency, the consumer is assumed to choose vehicle fuel-efficiency jointly with housing consumption and residential location. By incorporating the consumer׳s vehicle choice into the urban spatial model, we can represent the total amount of vehicle emissions released by the city residents. We first establish the well-known result that the congestion externality as a source of market failure is associated with excessive urban sprawl. We then show that vehicle emissions are an additional source of market failure, which also leads to excessive urban sprawl. The source of excessive sprawl arising from the emission externality is the use of larger and less-fuel efficient vehicles in more sprawled cities, which is different from that of the congestion externality. We also analyze the effect of the Corporate Average Fuel Economy (CAFE) standards on urban spatial structure and its efficacy as a second-best tool for correcting the emission externality.
High yield method for nanocrystalline zeolite synthesis

Nanocrystalline zeolites, such as silicalite-1 and zeolite Y, were synthesized in high yield by periodically removing nanocrystals from the synthesis solution and recycling the unused reagents, including the template and T-atom sources.
Effect of multiple engine placement on aeroelastic trim and stability of flying wing aircraft

Abstract Effects of multiple engine placement on flutter characteristics of a backswept flying wing resembling the HORTEN IV are investigated using the code NATASHA (Nonlinear Aeroelastic Trim And Stability of HALE Aircraft). Four identical engines with defined mass, inertia, and angular momentum are placed in different locations along the span with different offsets from the elastic axis while fixing the location of the aircraft c.g. The aircraft experiences body freedom flutter along with non-oscillatory instabilities that originate from flight dynamics. Multiple engine placement increases flutter speed particularly when the engines are placed in the outboard portion of the wing (60–70% span), forward of the elastic axis, while the lift to drag ratio is affected negligibly. The behavior of the sub- and supercritical eigenvalues is studied for two cases of engine placement. NATASHA captures a hump body-freedom flutter with low frequency for the clean wing case, which disappears as the engines are placed on the wings. In neither case is there any apparent coalescence between the unstable modes. NATASHA captures other non-oscillatory unstable roots with very small amplitude, apparently originating with flight dynamics. For the clean-wing case, in the absence of aerodynamic and gravitational forces, the regions of minimum kinetic energy density for the first and third bending modes are located around 60% span. For the second mode, this kinetic energy density has local minima around the 20% and 80% span. The regions of minimum kinetic energy of these modes are in agreement with calculations that show a noticeable increase in flutter speed if engines are placed forward of the elastic axis at these regions.
Secondary user friendly TDMA scheduling for primary users in cognitive radio networks

Cognitive radio technology is widely accepted as an efficient approach to solve the problem that the wireless spectrum has been getting scarcer and scarcer due to the rapid growth in the ubiquitous wireless applications. Several cognitive medium access control (MAC) protocols have been proposed for the secondary users (non-licensed users) to take advantage of the vacant channels whenever they are not occupied by the primary users (licensed users) in the wireless time division multiple access (TDMA)-based networks. In this paper, by exploiting the unique property of the wireless fading channel and cross-layer design technique, we develop a packets scheduling scheme for the primary users in the context of wireless TDMA networks, which is set up to operate friendly towards the secondary users in terms of vacant-channel probability. Our proposed scheme can be implemented with just slight modification on the traditional TDMA scheduling algorithm. We develop a rigorous queuing model and then quantitatively analyze the tradeoff among multiple performance metrics to identify when and where the cost for favoring the secondary users is worthy. The analytical results show that our proposed scheme can generate more vacant-channel opportunities for secondary users, at the expense of little increasing packet delay, as compared with the traditional wireless TDMA scheduling algorithm. In addition, since the implementation of our proposed scheme only needs little modification on the existing TDMA scheduling algorithm, our proposed scheme is a practical and cost-effective approach to increase the wireless spectrum utilization.
Palladium-catalyzed asymmetric allylic α-alkylation of acyclic ketones

The first example of Pd-catalyzed asymmetric allyl alkylation of the conformationally nonrigid acyclic ketone enolates is reported with excellent yields, regioselectivity, and enantioselectivity. The double bond geometry of the allyl enol carbonates affects its reactivity, selectivity, as well as the absolute configuration of the products. An opposite enantioselectivity from what is predicted by a direct attack of the enolate on the allyl moiety of the π-ally−Pd complex was observed. An alternative mechanism was proposed, which involves an inner sphere process of coordination of the enolate to Pd followed by reductive elimination.
Effects of ignition and wind on the transition to flame spread in a microgravity environment

Abstract A two-dimensional, time-dependent model is developed describing ignition and the subsequent transition to flame spread over a thermally thin cellulosic sheet heated by external radiation in a microgravity environment. The effects of a slow external wind (0–5 cm/s), and of the flux distribution of the external radiation on the transition are studied mainly in an atmosphere of 30% oxygen concentration. The ignition is initiated along the width of a sample strip, giving rise initially to two flame fronts spreading in opposite directions. The calculated results are compared with data obtained in the 2.2-s drop tower. Both experimental and calculated results show that with a slow, imposed wind, the upstream flame front (opposed mode) is stronger and slightly faster than the quiescent counterpart due to a greater supply of oxygen. However, the downstream flame front (concurrent mode) tends to die during the transition period. For all calculated cases studied in this work using the selected kinetic constants for the global one-step gas phase reaction, the downstream flame front dies out in oxygen concentrations up to 50% and wind velocity up to 5 cm/s. This is caused by the “oxygen shadow” cast by the upstream flame. The ignition delay time depends mainly on the peak flux of external radiation, whereas the transition time to steady state flame spread depends mainly on the broadness of the flux distribution. The broader the radiative flux distribution, the greater the transient flame spread rate due to the preheating of the sample ahead of the flame front by the external radiation and thus the greater the delay to steady state flame spread.
ATM support in a transparent network

It is shown how the variable size packet, source routing design on which the plaNET system was originally based is easily extended to provide support for ATM (asynchronous transfer mode) cells. The simultaneous support of various routing modes and packet formats is examined, mostly from the point of view of the necessary additional hardware and functionality. In particular, the components and processing needed to transparently support and take advantage of ATM in a plaNET network are examined. A major conclusion is that it is possible to combine the best attributes of variable size packets, source routing, cell routing, etc., without adding significantly to the cost of the network. >
FORAY-GEN: Automatic Generation of Affine Functions for Memory Optimizations

In today's embedded applications a significant portion of energy is spent in the memory subsystem. Several approaches have been proposed to minimize this energy, including the use of scratch pad memories, with many based on static analysis of a program. However, often it is not possible to perform static analysis and optimization of a program's memory access behavior unless the program is specifically written for this purpose. In this paper we introduce the FORAY model of a program that permits aggressive analysis of the application's memory behavior that further enables such optimizations since it consists of 'for' loops and array accesses which are easily analyzable. We present FORAY-GEN: an automated profile-based approach for extraction of the FORAY model from the original program. We also demonstrate how FORAY-GEN enhances applicability of other memory subsystem optimization approaches, resulting in an average of two times increase in the number of memory references that can be analyzed by existing static approaches.
Argus: A next-generation omnidirectional powerful radiotelescope

Abstract The time has come to seriously consider a fundamentally different approach for radiotelescopes. Compared to a conventional dish, an Argus timed array provides many advantages, including simultaneous omnidirectional high-gain sky coverage (no scanning), high sensitivity, high resolution, low sidelobes, detection of transient sources, retroactive observations, interference rejection, and high efficiency. An Argus array is less expensive since it takes advantage of mass production; has no large or moving parts; and is unaffected by gravity, sunlight or wind. The construction cost of a dish increases with time (since labor costs dominate), whereas the construction cost of an array decreases with time (since computing costs dominate). Hence an array must become less costly at some time, even if it's other advantages are ignored. We have successfully constructed and operated a prototype eight-element circular Argus array at 162 MHz. Continuing developments in computing power will make large arrays possible, and today modest arrays at lower frequencies are within reach. One fully implemented Argus array can simultaneously carry out all observations now being done by other comparable dish radiotelescopes.
An initial operational problem oriented medical record system: for storage, manipulation and retrieval of medical data

The ultimate role of the computer in the delivery of health services has yet to be defined. There may be profound implications in terms of quality of medical care, efficiency, economics of care, and medical research. Final judgments as to advisability and economic feasibility await the implementation of prototype total medical information systems and further technical developments directed toward lowering the high cost of currently developing systems. Development of less expensive hardware and real-time application of the present hardware and software must go on in parallel. We have been involved in the latter, and an experimental time-shared medical information system has been developed for storing and retrieving the total medical record, including both the narrative and the numeric data. This development has integrated the Problem Oriented Medical Record, a means of organizing medical data around a patient's problems, with a touch sensitive cathode ray tube terminal that allows structured input (with additional keyboard entry capability) by directly interfaced medical users (in particular the physician and the nurse).
Hedonic wage equations for higher education faculty

This paper discusses the use of hedonic techniques to theoretically and empirically understand the wages of higher education faculty. The paper first presents theoretical models of department and faculty choice. These models represent a synthesis of prior work in the hedonic area. The models imply a hedonic wage equation for faculty with wages dependent on productivity, departmental amenities and locational amenities. The theoretical discussion is followed by exploratory and illustrative empirical work. In summary, the reported regressions show that increased teaching loads and secretaries per faculty member tend to decrease salaries while increasing referred journal articles, hotter than average summers, colder than average winters and a Ph.D. program tend to increase professor’s salaries.  2002 Elsevier Science Ltd. All rights reserved.
Quantifying the Importance of Orbital Over Spin Correlations in δ-Pu Within Density-Functional Theory

The electronic structure of plutonium is studied within the density-functional theory (DFT) model. Key features of the electronic structure are correctly modeled and bonding, total energy, and electron density of states are all consistent with measure data, although the prediction of magnetism is not consistent with many observations. Here we analyze the contributions to the electronic structure arising from spin polarization, orbital polarization, and spin-orbit interaction. These effects give rise to spin and orbital moments that are of nearly equal magnitude, but anti-parallel, suggesting a magnetic-moment cancellation with a zero total moment. Quantifying the spin versus orbital effects on the bonding, total energy, and electron spectra it becomes clear that the spin polarization is much less important than the orbital correlations. Consequently, a restricted DFT approach with a non-spin polarized electronic structure can produce reasonable equation-of-state and electron spectra for δ-Pu when the orbital effects are accounted for. Hence, we present two non-magnetic models. One in which the spin moment is canceled by the orbital moment and another in which the spin moment (and therefore the orbital moment) is restricted to zero.
THE NATURE AND CAUSE OF SPECTRAL VARIABILITY IN LMC X-1

We present the results of a long-term observation campaign of the extragalactic wind-accreting black hole X-ray binary LMC X-1, using the Proportional Counter Array on RXTE. The observations show that LMC X-1's accretion disk exhibits an anomalous temperature-luminosity relation. We use deep archival RXTE observations to show that large movements across the temperature-luminosity space occupied by the system can take place on timescales as short as half an hour. These changes cannot be adequately explained by perturbations that propagate from the outer disk on a viscous timescale. We propose instead that the apparent disk variations reflect rapid fluctuations within the Compton upscattering coronal material, which occults the inner parts of the disk. The expected relationship between the observed disk luminosity and apparent disk temperature derived from the variable occultation model is quantitatively shown to be in good agreement with the observations. Two other observations support this picture: an inverse correlation between the flux in the power-law spectral component and the fitted inner-disk temperature, and a near-constant total photon flux, suggesting that the inner disk is not ejected when a lower temperature is observed.
Multivariate Regression with Calibration

We propose a new method named calibrated multivariate regression (CMR) for fitting high dimensional multivariate regression models. Compared to existing methods, CMR calibrates the regularization for each regression task with respect to its noise level so that it is simultaneously tuning insensitive and achieves an improved finite-sample performance. Computationally, we develop an efficient smoothed proximal gradient algorithm which has a worst-case iteration complexity O(1/ ∈), where ∈ is a pre-specified numerical accuracy. Theoretically, we prove that CMR achieves the optimal rate of convergence in parameter estimation. We illustrate the usefulness of CMR by thorough numerical simulations and show that CMR consistently outperforms other high dimensional multivariate regression methods. We also apply CMR on a brain activity prediction problem and find that CMR is as competitive as the handcrafted model created by human experts.
Shape- and Size-Specific Chemistry of Ag Nanostructures in Catalytic Ethylene Epoxidation

Catalytic selectivity in the epoxidation of ethylene to form ethylene oxide on alumina-supported silver catalysts is dependent on the geometric structure of catalytically active Ag particles and reaction conditions. Shape and size controlled synthesis of Ag nanoparticles is used to show that silver nanocubes exhibit higher selectivity than nanowires and nanospheres. For a given shape, larger particles offer improved selectivity. The enhanced selectivity toward ethylene oxide is attributed to the nature of the exposed Ag surface facets; Ag nanocubes and nanowires are dominated by (100) surface facet and Ag nanospheres are dominated by (111). Furthermore, the concentration of undercoordinated surface sites is related to diminished selectivity to ethylene oxide. We demonstrate that a simple model can account for the impact of chemical and physical factors on the reaction selectivity. These observations have also been used to design a selective catalyst for the ethylene epoxidation reaction.
LOW-FREQUENCY GRAVITATIONAL WAVES FROM WHITE DWARF MACHO BINARIES

The possibility that Galactic halo MACHOs are white dwarfs has recently attracted much attention. Using the known properties of white dwarf binaries in the Galactic disk as a model, we estimate the possible contribution of halo white dwarf binaries to the low-frequency (10-5 Hz < f < 10-1 Hz) gravitational wave background. Assuming the fraction of white dwarfs in binaries is the same in the halo as in the disk, we find the confusion background from halo white dwarf binaries could be 5 times stronger than the expected contribution from Galactic disk binaries, dominating the response of the proposed space-based interferometer LISA. Low-frequency gravitational wave observations will be the key to discovering the nature of the dark MACHO binary population.
Minds, Brains, and Programs

This article can be viewed as an attempt to explore the consequences of two propositions. (1) Intentionality in human beings (and animals) is a product of causal features of the brain I assume this is an empirical fact about the actual causal relations between mental processes and brains It says simply that certain brain processes are sufficient for intentionality. (2) Instantiating a computer program is never by itself a sufficient condition of intentionality The main argument of this paper is directed at establishing this claim The form of the argument is to show how a human agent could instantiate the program and still not have the relevant intentionality. These two propositions have the following consequences (3) The explanation of how the brain produces intentionality cannot be that it does it by instantiating a computer program. This is a strict logical consequence of 1 and 2. (4) Any mechanism capable of producing intentionality must have causal powers equal to those of the brain. This is meant to be a trivial consequence of 1. (5) Any attempt literally to create intentionality artificially (strong AI) could not succeed just by designing programs but would have to duplicate the causal powers of the human brain. This follows from 2 and 4. "Could a machine think?" On the argument advanced here only a machine could think, and only very special kinds of machines, namely brains and machines with internal causal powers equivalent to those of brains And that is why strong AI has little to tell us about thinking, since it is not about machines but about programs, and no program by itself is sufficient for thinking.
Neutron stars as probes of extreme energy density matter

Neutron stars have long been regarded as extraterrestrial laboratories from which we can learn about extreme energy density matter at low temperatures. In this article, some of the recent advances made in astrophysical observations and related theory are highlighted. Although the focus is on the much needed information on masses and radii of several individual neutron stars, the need for additional knowledge about the many facets of neutron stars is stressed. The extent to which quark matter can be present in neutron stars is summarized with emphasis on the requirement of non-perturbative treatments. Some longstanding and new questions, answers to which will advance our current status of knowledge, are posed.
Relationship of physical symptoms and physical functioning to depression in patients with heart failure

Abstract Objective: The purpose of this study was to determine the relative contribution of physical symptoms and physical functioning to depression in adult patients with heart failure during hospitalization and the early postdischarge period. Design: An exploratory, correlational longitudinal design was used. Patients: The sample included 170 subjects with heart failure. Results: Subjects’ mean scores on the depression scale indicated that subjects were not depressed on average; however, 30% of the sample (n = 52) had scores indicative of clinical depression. Both physical symptoms (r = 0.48) and physical functioning (r = –0.32) were moderately correlated with depression. Physical symptoms contributed 13% uniquely to the variance in depression while physical functioning contributed only 2% uniquely to the variance in depression. Multiple regression analyses indicated that physical symptomatology is more closely related to depression than is physical functioning in adults with heart failure. Conclusions: This study showed the patients with heart failure who had increased physical symptoms and poorer physical functioning reported increased symptoms of depression. Physical symptoms explained a greater portion of the variance in depression than did physical functioning. Thus, it appears that patients with heart failure are affected emotionally by both their physical symptoms and their limitations in their physical functioning, but depression is more strongly related to having more physical symptoms than having greater limitations in physical functioning. (Heart Lung® 2001;30:98-104.)