cssi/SciSciGPT-SciSciNet huggingface dataset:
Updating Inertial Navigation Systems with VOR/DME Information

Updating an inertial navigation system (INS) with VOR/DME information (from one or two stations) by means of a maximum-likelihood filter is shown to result in substantial improvements in navigational accuracy over that obtained by the use of a single VOR/DME (current practice). When continuously updating, the use of a high- quality INS (0.01 °/hr gyro drift) instead of a low-quality INS (1.0°/hr gyro drift) does not substantially improve position accuracy. In-flight alignment (or realignment) of an INS to an accuracy comparable to that of ground alignment can be accomplished by using two DME's. Several reduced-order suboptimal filters were found to perform nearly optimally. HE primary navigation aid for civil aircraft flying in the airspace of most of the developed countries of the world is the VOR/DME system. The VOR (Very high-frequency Omni- Range) and the DME (Distance Measuring Equipment) enable onboard determination of an aircraft's bearing relative to north at the fixed ground station and slant range from the station, respectively. Current use of the VOR/DME system involves primarily radial navigation, i.e., aircraft fly directly to or from the ground stations. However, some beginnings have been made in using the VOR/ DME system for area navigation, i.e., use of the system without being restricted to fly directly to or from the ground stations. The number of commercial airliners equipped with inertial navigation systems (INS's) is steadily increasing. The systems now onboard aircraft utilize a gyro-stabilized platform on which the accelerometers are mounted. The platform is aligned before takeoff to the desired orientation. Due to alignment errors and in-flight random disturbances such as gyro drift, scale-factor errors, and accelerometer bias errors, errors in the desired orientation of the platform increase with time. This results in increasing position and velocity errors. Thus, improving navi- gational accuracy by in-flight realignment of an INS is an interesting possibility. Position errors are generally greater for area than for radial navigation. This comes about because the position error resulting from a VOR angular error increases with distance from the station; and an aircraft is farther, on the average, from the VOR stations for area than for radial navigation. Hence, improved navigational accuracy is required to obtain an accuracy for area navigation comparable to that of present-day radial navigation. The availability of an onboard computer to do the triangulation computations required for area navigation suggests Presented as Paper 72-846 at the AIAA Guidance and Control
A highly active magnetically recoverable nano ferrite-glutathione-copper (nano-FGT-Cu) catalyst for Huisgen 1,3-dipolar cycloadditions

1,2,3-Triazoles were synthesized in water using magnetically recoverable heterogeneous Cu catalyst via one-pot multi component reaction using MW irradiation. Aqueous reaction medium, easy recovery of the catalyst using an external magnet, efficient recycling, and the high stability of the catalyst renders the protocol economic and sustainable.
Lubrication with sputtered MoS2 films

Sputtered MoS2films (2000–6500 A) were deposited on highly polished metal surfaces. These films have a low coefficient of friction (0.03–0.04) at speeds of 40–80 rpm and loads of 250–1000 grams. At loads of 250 grams the wear lives are over 0.5 million cycles, but at 1000 gram loads, it decreases to 38,000 cycles. Friction experiments and tensile tests have indicated that sputtered films have a strong adherence to metal surfaces. Electron transmission, diffraction and scanning electron microscopy show that these films have an extremely small particle size, less than 30 A in diameter, and are very dense and free from observable pinholes. The high kinetic energy of these sputtered species, the submicroscopic particle size and the sputter-etched substrate surface is responsible for strong adhesion and cohesion of the sputtered film. Presented at the first ASLE International Conference on Solid Lubrication held in Denver, Colorado, August 24–27, 1971
Mass along the Line of Sight to the Gravitational Lens B1608+656: Galaxy Groups and Implications for H_0

We report the discovery of four groups of galaxies along the line of sight to the B1608+656 gravitational lens system. One group is at the redshift of the primary lensing galaxy (z = 0.631) and appears to have a low mass, with eight spectroscopically confirmed members and an estimated velocity dispersion of 150 ± 60 km s^(-1). The three other groups are in the foreground of the lens. These groups contain ~10 confirmed members each and are located at redshifts of 0.265, 0.426, and 0.52. Two of the three additional groups are centered roughly on the lens system, while the third is centered ~1' south of the lens. We investigate the effect of each of the four groups on the gravitational lensing potential of the B1608+656 system, with a particular focus on the implications for the value of H_0 derived from this system. We find that each group provides an external convergence of ~0.005-0.060, depending on the assumptions made in the calculation. For the B1608+656 system, the stellar velocity dispersion of the lensing galaxy has been measured, thus breaking the mass sheet degeneracy due to the group that is physically associated with the lens. The effect of the other groups along the line of sight can be folded into the overall uncertainties due to large-scale structure (LSS) along the line of sight. Because B1608+656 appears to lie along an overdense line of sight, the LSS will cause the measurement of H_0 to be biased high for this system. This effect could be 5% or greater.
(−)-Carbodine: Enantiomeric synthesis and in vitro antiviral activity against various strains of influenza virus including H5N1 (avian influenza) and novel 2009 H1N1 (swine flu)

Abstract Enantiomerically pure cyclopentyl cytosine [( − )-carbodine 1 ] was synthesized from d -ribose and evaluated for its anti-influenza activity in vitro in comparison to the (+)-carbodine, (±)-carbodine and ribavirin. ( − )-Carbodine 1 exhibited potent antiviral activity against various strains of influenza A and B viruses.
AFIS data compression: an example of how domain specific compression algorithms can produce very high compression ratios

This article describes the development and implementation of a data compression algorithm designed specifically for fingerprints, referred to as GBP compression. The algorithm is herein discussed. Data Compression algorithms can be designed for general applications, meaning the input data is unknown. This is more commonly referred to as generic data. [LI01] Or, data compression algorithms can be designed for specific applications. e.g. AFIS [Automated Fingerprint Identification Systems] "When the input is known, higher compression ratios can be achieved with the knowledge of the input data stream." To-date, the highest compression ratio for an unknown input data stream, for all data compression algorithms, is JPEG with an average compression ratio range of 1:17 -- 1:23. [PEN03] The algorithm herein discussed, has a compression ratio range of 1:68 -- 1:92. There is a value, time and place for each design method - generic or specific - depending upon a variety of factors. Due to the nature of the use of AFIS for law enforcement and incrimination as well as criminal conviction, there are social issues that make data integrity of paramount concern. This factor influences algorithm selection and design. A lossless algorithm is a must! Also, the nature of AFIS is such that it operates across borders and between states, municipalities and jurisdictions. In addition to the usual issues and resistance to accepting new technology, including software [e.g. resistance to change, fear of system failure, etc.], there are the issues of changing engineering standards [hardware and software] which are governmentally determined as well as governmental policy decisions. Likewise, the portability required in implementing a new algorithm, will have to deal with a variety of hardware and software; as well as be designed to integrate into existing systems. This integration must include the ability to incorporate existing JPEG data files, from existing police databases. This requires a handshaking of standards and conversion programs that maintain data integrity. In addition, there is an in depth discussion of the limits of compression with a novel perspective.
A Transcriptional Signaling Pathway in the IFN System Mediated by 2′-5′-Oligoadenylate Activation of RNase L

Virus replication in higher vertebrates is restrained by IFNs that cause cells to transcribe genes encoding antiviral proteins, such as 2′-5′ oligoadenylate synthetases. 2′-5′ oligoadenylate synthetase is stimulated by dsRNA to produce 5′-phosphorylated, 2′-5′-linked oligoadenylates (2-5A), whose function is to activate RNase L. Although RNase L is required for a complete IFN antiviral response and mutations in the RNase L gene (RNASEL or HPC1) increase prostate cancer rates, it is unknown how 2-5A affects these biological endpoints through its receptor, RNase L. Presently, we show that 2-5A activation of RNase L produces a remarkable stimulation of transcription (≥20-fold) for genes that suppress virus replication and prostate cancer. Unexpectedly, exposure of DU145 prostate cancer cells to physiologic levels of 2-5A (0.1 μM) induced approximately twice as many RNA species as it down-regulated. Among the 2-5A-induced genes are several IFN-stimulated genes, including IFN-inducible transcript 1/P56, IFN-inducible transcript 2/P54, IL-8, and IFN-stimulated gene 15. 2-5A also potently elevated RNA for macrophage inhibitory cytokine-1/nonsteroidal antiinflammatory drug-activated gene-1, a TGF-β superfamily member implicated as an apoptotic suppressor of prostate cancer. Transcriptional signaling to the macrophage inhibitory cytokine-1/nonsteroidal antiinflammatory drug-activated gene-1 promoter by 2-5A was deficient in HeLa cells expressing a nuclease-dead mutant of RNase L and was dependent on the mitogen-activated protein kinases c-Jun N-terminal kinase and extracellular signal-regulated kinase, both of which were activated in response to 2-5A treatments. Because 2-5A and RNase L participate in defenses against viral infections and prostate cancer, our findings have implications for basic cellular mechanisms that control major pathogenic processes.
Feedback In Analog And Digital Optical Image Processing: A Review

The use of feedback for enhancing the capabilities of optical image processing systems as well as introducing new operational characteristics is the subject of much recent interest. This paper presents a review of the various processing schemes utilizing feedback developed in the past two years. Such schemes are categorized into optical analog and digital optical techniques. Analog processors with feedback can achieve greater effective dynamic range and a wider variety of transfer functions. Incorporation of gain into the feedback loop helps enhance these aspects, and further adds the possibility of constructing an optical operational amplifier. Nonlinear and space-variant response can also be obtained. Digital optical systems operate on binary rather than analog images. The use of feedback leads to the realization of image thresholding devices and optical flip-flop memories (both of which are vitally important to any digital system) using materials without natural hysteresis or sharp nonlinear characteristics. Existing schemes using dif-ferent materials and configurations will be reviewed.
Asymptotic theory for quantum Bose systems with many degrees of freedom

We construct asymptotic expansions of Laplace type for the time-dependent quantum averages for Bose systems with many degrees of freedom, initially populated in coherent states. These solutions are localized in phase space, and they are different from the usual oscillating asymptotics for the quasi-classical wave functions. These expansions are valid on any fixed time interval, and caustics do not contribute to the asymptotics.
Photonic density of states of two-dimensional quasicrystalline photonic structures

A large photonic band gap (PBG) is highly favorable for photonic crystal devices. One of the most important goals of PBG materials research is identifying structural design strategies for maximizing the gap size. We provide a comprehensive analysis of the PBG properties of two-dimensional (2D) quasicrystals (QCs), where rotational symmetry, dielectric fill factor, and structural morphology were varied systematically in order to identify correlations between structure and PBG width at a given dielectric contrast (13:1, Si:air). The transverse electric (TE) and transverse magnetic (TM) PBGs of 12 types of QCs are investigated (588 structures). We discovered a 12mm QC with a 56.5% TE PBG, the largest reported TE PBG for an aperiodic crystal to date. We also report here a QC morphology comprising ''throwing star''-like dielectric domains, with near-circular air cores and interconnecting veins emanating radially around the core. This interesting morphology leads to a complete PBG of {approx}20% , which is the largest reported complete PBG for aperiodic crystals.
Oligomerization of ribonucleotides on montmorillonite: reaction of the 5'-phosphorimidazolide of adenosine.

The regiospecific formation of oligomers from unblocked monomers in aqueous solution is one of the central tenets in research on the origins of life on earth. Direct experimental support for this hypothesis has been obtained in studies of the condensation of the 59-phosphorimidazolide of adenosine (ImpA) with itself and with P1,P2-diadenosine-59,59-pyrophosphate (AppA) in water in the presence of a montmorillonite clay. Oligomers of up to ten nucleotides in length are formed. Analysis of the trimers, tetramers, and pentamers formed from a 9:1 ImpA:AppA mixture has shown that 85% of the bonds formed are 39,59-linked and that any 29,59-linkages present are at the phosphodiester bond next to the 39-terminus of the oligomers.
Explaining Diversity: Symmetry-Breaking in Complementarity Games

Strategic complementarity games have found applications in many fields, including macroeconomics, development, and labor economics.' They provide a useful framework within which to address questions like: "What generates the disparity across regions and countries?" "Why are there booms and recessions?" and "What causes gender and race discrimination in the labor market?" In short, they help us think about the diversity and variations across space, time, and groups. The literature on complementarity games has emphasized coordination failures as the key notion to understand these questions. This paper argues that such emphasis is misplaced; the key to understand the diversity is symmetrybreaking. The notion of coordination failures is not only irrelevant, but also misleading when thinking about the diversity.
An EM algorithm for continuous-time bivariate Markov chains

We study properties and parameter estimation of a finite-state, homogeneous, continuous-time, bivariate Markov chain. Only one of the two processes of the bivariate Markov chain is assumed observable. The general form of the bivariate Markov chain studied here makes no assumptions on the structure of the generator of the chain. Consequently, simultaneous jumps of the observable and underlying processes are possible, neither process is necessarily Markov, and the time between jumps of each of the two processes has a phase-type distribution. Examples of bivariate Markov chains include the Markov modulated Poisson process and the batch Markovian arrival process when appropriate modulo counts are used in each case. We develop an expectation-maximization (EM) procedure for estimating the generator of a bivariate Markov chain, and we demonstrate its performance. The procedure does not rely on any numerical integration or sampling scheme of the continuous-time bivariate Markov chain. The proposed EM algorithm is equally applicable to multivariate Markov chains.
The geometry of surface-by-free groups

We show that every word hyperbolic, surface-by-(noncyclic) free group \( \Gamma \) is as rigid as possible: the quasi-isometry group of \( \Gamma \) equals the abstract commensurator group Comm(\( \Gamma \)), which in turn contains \( \Gamma \) as a finite-index subgroup. As a corollary, two such groups are quasiisometric if and only if they are commensurable, and any finitely-generated group quasi-isometric to \( \Gamma \) must be weakly commensurable with \( \Gamma \). We use quasi-isometries to compute Comm(\( \Gamma \)) explicitly, an example of how quasi-isometries can actually detect finite-index information. The proofs of these theorems involve ideas from coarse topology, Teichmuller geometry, pseudo-Anosov dynamics, and singular SOLV geometry.
The effects of structural change and economic liberalisation on gender wage differentials in South Korea and Taiwan

This paper investigates the sources of divergent trends in gender wage differentials in two important newly industrialised economies (NIEs), South Korean and Taiwan. As these economies have entered the "post-industrial" phase of development, gender wage differentials in Taiwan's manufacturing sector have widened, while in Korea they have narrowed. Decomposition analysis is used to broadly identify sources of change in gender wage differentials. Multivariate regression analysis is relied on to differentiate the impact on the gender wage gap of (1) macro-levels policies, (2) institutional factors, and (3) shifts in labour demand and supply. In addition to the predictable effects of several standard supply-side variables, in Taiwan physical capital mobility is found to have contributed to a wider gender earnings gap. Women's greater concentration in industries where capital is mobile may explain this result. The effects of capital mobility in Korea appears to differ, which may be due to the dissimilar characters of outward FDI from that country. Copyright 2000 by Oxford University Press.
Synthesis of (R)-lysothiophosphatidic Acid and (R)-thiophosphatidic acid

Abstract (R)-Thiophosphatidic acid and (R)-lysothiophosphatidic acid were obtained in an efficient synthesis from a chiral glycerol precursor via sulfurization of a bis(2-cyanoethyl) phosphite triester.
Complementarities Between Organizational IT Architecture and Governance Structure

This study addresses the theoretically neglected interplay between organizational information technology (IT) architecture and IT governance structure in shaping IT alignment. We theoretically develop the idea that IT architecture modularity helps sustain IT alignment by increasing IT agility, and that decentralization of IT governance strengthens this relationship. IT architecture therefore complements IT governance structure. Tests of the proposed mediated-moderation model using data from 223 organizations support these ideas. Implications for theory and practice are also discussed.
Tandem [4+2]/[3+2] Cycloadditions of Nitroalkenes.

Insofar as one of the fundamental objectives of organic synthesis is the construction of complex molecules from simpler ones, the importance of synthetic efficiency becomes immediately apparent and has been well-recognized.1 The increase in molecular complexity2 that necessarily accompanies the course of a synthesis provides a guide (and a measure) of synthetic efficiency. As a goal, one would like to optimally match the change in molecular complexity at each step with reactions of comparable synthetic complexity. Thus, the creation of many bonds, rings, and stereocenters in a single transformation is a necessary (though not sufficient) condition for high synthetic efficiency. The ultimate, perfect match would constitute single-step syntheses. More realistically, especially in view of the desire for general synthetic methods, the combination of mulScott E. Denmark was born in New York in 1953. He obtained an S.B. degree from MIT in 1975 and carried out research with Daniel Kemp and Richard Holm. His graduate studies at the ETH-Zurich with Albert Eschenmoser culminated with the D. Sc. Tech. degree in 1980. That same year he joined the faculty of the University of Illinois at UrbanasChampaign and was promoted to full professor in 1987. In 1991 he was named the Reynold C. Fuson Professor of Chemistry. His research interests are primarily in the invention of new synthetic reactions, structure and reactivity of organoelement reagents, and the origin of stereocontrol in fundamental carbon−carbon bond forming reactions.
A Study of Operands in Terms of Maximal Generalized Orbits

A left operand X of a monoid S is called saturated if every generalized orbit (g.o.) in X is contained in a union of others. Every operand has a natural decomposition as a union of an operand admitting an irredundant cover by maximal g.o. ′s and of a saturated operand. There is a descending chain of suboperands of an operand, defined in terms of maximal g.o. ′s, which leads to the definition of the saturation length of an operand. S has no saturated operands if and only if S satisfies the a.c.c. on orbits. Full proofs will be given in [2].
Direct imaging of spatially varying potential and charge across internal interfaces in solids.

Transmission electron holography is utilized to study the electrostatic potential and associated space charge across grain boundaries in SrTiO{sub 3}. While pristine boundaries show only the effect of a reduction in density of atoms, doped boundaries indicate the presence of potential barriers and associated space charge due to accumulation of charged point defects. This Letter demonstrates the viability of electron holography as a bulk sensitive tool to directly image and quantify the magnitude, sign, and spatial extent of electrical potential and charge across internal interfaces in solids. {copyright} {ital 1995} {ital The} {ital American} {ital Physical} {ital Society}.
Respiratory drive during status epilepticus and its treatment: comparison of diazepam and lorazepam.

In order to examine the respiratory effects of tonic-clonic seizures and their treatment with i.v. diazepam or lorazepam, we utilized a spontaneously breathing piglet seizure model. A tracheostomy, arterial catheter, and epidural electrodes were inserted and pigs were maintained under ketamine anesthesia. After baseline recordings, seizures were induced with a pentylenetetrazol (PTZ) bolus and a 20 min infusion (5-6 mg/kg/min). After 10 min of PTZ infusion, randomly assigned animals received diazepam (D; N = 7; 0.5 mg/kg), lorazepam (L; N = 7; 0.2 mg/kg), or 0.9% saline (C; N = 7; controls) by rapid peripheral vein injection. Minute ventilation (Ve), Pa(CO2), and the pressure change in response to airway occlusion at end-expiration (P0.1) were measured at standard intervals. All groups had comparable increases in respiratory drive during untreated seizures. Changes in Ve and P0.1 were reduced to at or below baseline values in groups D and L, but not C, from 2 to 45 min after treatment (P < 0.05). No significant changes were observed in Pa(CO2) after either intervention. Following anticonvulsants, the cumulative duration of seizures was significantly reduced in L and D groups, compared to C (P < 0.05). We conclude that increases in respiratory drive occur during tonic-clonic seizures induced with PTZ. Amelioration of seizure activity with lorazepam or diazepam results in a reduction in respiratory drive, but not respiratory failure, in this tracheostomized model.
Activation of Si–Si Bonds for Copper(I)-Catalyzed Conjugate Silylation

Several alkyl- and vinylsilanes were prepared through the copper(I)-catalyzed conjugate silylation of α,β-unsaturated compounds. Optimal reaction conditions were first investigated to realize the conjugate addition of a nucleophilic silicon species to poorly electrophilic acceptors such as phenylvinyl sulfone by cleavage of the Si–Si bond of a disilane reagent. The scope of this reaction was extended to various electrophiles bearing different electron-withdrawing groups and afforded the desired substituted alkyl- and vinylsilanes. Among the wide range of commercially available disilanes, the reactivities of alkyl-, aryl-, and ethoxydisilane were also examined.
Properties that characterize LOGCFL

Abstract Two properties, called semi-unboundedness and polynomial proof-size, are identified as key properties shared by the definitions of LOGCFL on several models of computations. The semi-unboundedness property leads to the definition of semi-unbounded fan-in circuit families. These are circuits obtained from unbounded fan-in circuits by restricting the fan-in of gates of one type. A new characterization of LOGCFL is obtained on such a model in which the fan-in of the AND gates are bounded by a constant. This property also suggests new characterizations of LOGCFL on the following models: alternating Turing machines, nondeterministic auxiliary pushdown automata, and bounded fan-in Boolean circuits.
Complex equiangular cyclic frames and erasures

We derive various interesting properties of complex equiangular cyclic frames for many pairs (n, k) using Gauss sums and number theory. We further use these results to study the random and burst errors of some special classes of complex equiangular cyclic (n, k) frames.
Recycling of carbon dioxide to methanol and derived products – closing the loop

Starting with coal, followed by petroleum oil and natural gas, the utilization of fossil fuels has allowed the fast and unprecedented development of human society. However, the burning of these resources in ever increasing pace is accompanied by large amounts of anthropogenic CO2 emissions, which are outpacing the natural carbon cycle, causing adverse global environmental changes, the full extent of which is still unclear. Even through fossil fuels are still abundant, they are nevertheless limited and will, in time, be depleted. Chemical recycling of CO2 to renewable fuels and materials, primarily methanol, offers a powerful alternative to tackle both issues, that is, global climate change and fossil fuel depletion. The energy needed for the reduction of CO2 can come from any renewable energy source such as solar and wind. Methanol, the simplest C1 liquid product that can be easily obtained from any carbon source, including biomass and CO2, has been proposed as a key component of such an anthropogenic carbon cycle in the framework of a “Methanol Economy”. Methanol itself is an excellent fuel for internal combustion engines, fuel cells, stoves, etc. It's dehydration product, dimethyl ether, is a diesel fuel and liquefied petroleum gas (LPG) substitute. Furthermore, methanol can be transformed to ethylene, propylene and most of the petrochemical products currently obtained from fossil fuels. The conversion of CO2 to methanol is discussed in detail in this review.
Identification of purine deoxyribonucleoside anomers by two dimensional NOESY NMR

Abstract Patterns of NOE crosspeaks in two dimensional 1 H NOESY spectra of purine deoxyribonucleosides are characteristic for the β and α anomers. Certain 1 H chemical shifts are characteristic for 7 and 9 regioisomers. NOE intensities, although qualitatively consistent with interproton distance ranges in N and S conformers, are insufficient for complete conformational analysis of nucleosides.
Modeling of a Hydraulic Wind Power Transfer Utilizing a Proportional Valve

Hydraulic circuits can transfer remarkable amounts of energy in the desired direction without taking large space. To implement this technology for harvesting the energy of wind appropriately, models of the system are required. Hydraulic wind power technology has the benefits of eliminating expensive and bulky variable ratio gearbox and its costly maintenance, while enabling the integration of multiple wind turbines in a single generation unit. In this paper, the dynamics of different hydraulic elements are studied, nonlinearities are taken into account, pressure dynamics in different parts of the system are studied, and the motor load effects are considered. Based on these considerations, a novel nonlinear state-space representation of the system is introduced. Results of the mathematical model and the experimental data are compared to verify the proposed model. The comparison demonstrated that the mathematical model captures all major characteristics of the hydraulic circuit and can model the system behavior under different operating conditions.
How Far From Stability Can We Go Using Gammasphere and the FMA

This paper presents new results obtained using the US national gamma-ray facility Gammasphere, which has been operating at the ATLAS accelerator at Argonne National Laboratory since January 1998. Gammasphere was built at Lawrence Berkeley Laboratory and used primarily as a powerful spectrometer for studying nuclei at the highest spins.
A lattice compress-and-forward scheme

We present a nested lattice-code-based strategy that achieves the random-coding based Compress-and-Forward (CF) rate for the three node Gaussian relay channel. To do so, we first outline a lattice-based strategy for the (X + Z 1 , X + Z 2 ) Wyner-Ziv lossy source-coding with side-information problem in Gaussian noise, a re-interpretation of the nested lattice-code-based Gaussian Wyner-Ziv scheme presented by Zamir, Shamai, and Erez. We use the notation (X + Z 1 , X + Z 2 ) Wyner-Ziv to mean that the source is of the form X + Z 1 and the side-information at the receiver is of the form X+Z 2 , for independent Gaussian X, Z 1 and Z 2 . We use this (X + Z 1 , X + Z 2 ) Wyner-Ziv scheme to implement a “structured” or lattice-code-based CF scheme for the Gaussian relay channel which achieves the same rate as the Cover-El Gamal CF rate achieved by random Gaussian codebooks.
Optimum design of a composite structure with three types of manufacturing constraints

References ill, J. A. F., Wardlaw, A. B., Jr., Pronchick, S. W., and Holmes, J. E., "Verification Tests in the Mach 14 Nozzle of the Hypervelocity Tunnel at NSWC (White Oak)," AIAA Paper 77-150, Jan. 1977. Kavetsky, R., "Mach 10 High Reynolds Number Development in the NSWC Hypervelocity Facility," Naval Surface Warfare Center, TR 83-526, White Oak, MD, June 1984. Hedlund, E. R., and Ragsdale, W. C., "Improvements in Low Reynolds Number Testing in the NSWC Hypervelocity Wind Tunnel #9," AIAA Paper 85-0226, Jan. 1985. Ragsdale, W. C., "Hypervelocity Wind Tunnel 9 Test Planning Guide," 2nd ed., Naval Surface Warfare Center, MP 88-200, White Oak, MD, Oct. 1989. Hedlund, E. R., Higgins, C. W., Rozanski, C. S., Fehring, N. P., and Krueger, D., "The New High Reynolds Number Mach 8 Capability in the NSWC Hypervelocity Wind Tunnel #9," AIAA Paper 90-1379, June 1990. Trolier, J. W., Sinha, N., and York, B., "Mach 8 Nozzle Design Verification, Science Applications International Corp., SAIC-88/ 1788, Fort Washington, PA, July 1988. Anon., "Report 1135: Equations, Tables, and Charts for Compressible Flow," NASA Ames Research Center, Moffett Field, CA, 1953. Hecht, A. M., Nestler, D. E., and Richbourg, D. H., "Application of a Three-Dimensional Viscous Computer Code to Reentry Vehicle Design," AIAA Paper 79-0306, Jan. 1979. Van Driest, E. R., "The Problem of Aerodynamic Heating," Aeronautical Engineering Review, Vol. 15, No. 10, Oct. 1956, pp. 26-41.
What do we know about Lorentz invariance

The realization that Planck-scale physics can be tested with existing technology through the search for spacetime-symmetry violation brought about the development of a comprehensive framework, known as the gravitational standard-model extension (SME), for studying deviations from exact Lorentz and CPT symmetry in nature. The development of this framework and its motivation led to an explosion of new tests of Lorentz symmetry over the past decade and to considerable theoretical interest in the subject. This work reviews the key concepts associated with Lorentz and CPT symmetry, the structure of the SME framework, and some recent experimental and theoretical results.
Global Properties of the Globular Cluster Systems of Four Spiral Galaxies

We present results from a wide-field imaging study of the globular cluster (GC) systems of a sample of edge-on, Sb-Sc spiral galaxies ~7-20 Mpc away. This study is part of a larger survey of the ensemble properties of the GC populations of giant galaxies. We imaged the galaxies in BVR filters with large-format CCD detectors on the WIYN 3.5 m telescope to projected radii of ~20-40 kpc. For four galaxies (NGC 2683, NGC 3556, NGC 4157, and NGC 7331), we quantify the radial distributions of the GC systems and estimate the total number, luminosity- and mass-normalized specific frequencies (SN and T), and blue (metal-poor) fraction of GCs. A fifth galaxy (NGC 3044) was apparently too distant for us to have detected its GC system. Our SN for NGC 2683 is 2.5 times smaller than the previously published value, likely due in part to reduced contamination from non-GCs. For the spiral galaxies analyzed for the survey to date, the average number of GCs is 170 ± 40, and the weighted mean values of SN and T are 0.8 ± 0.2 and 1.4 ± 0.3, respectively. We use the survey data to derive a relationship between the radial extent of the GC system and host galaxy mass over a factor of 20 in mass. Finally, we confirm the trend, identified in previous survey papers, of increasing specific frequency of metal-poor GCs with increasing galaxy mass. We compare the data with predictions from a simple model and show that carefully quantifying the numbers of metal-poor GCs in galaxies can constrain the formation redshifts of the GCs and their host galaxies.
Electromagnetic Penetration Through Apertures in Conducting Surfaces

In designing hardened systems, one must be able to characterize as well as quantitatively determine the penetration of EMP signals through apertures of general shapes in structures of varying conflgurations. In this paper a tutorial review of a number of methods for analyzing such aperture problems is presented with an emphasis on techniques. The discussion presented herein is reasonably self-contained and is supplemented by references to classical as well as current approaches to the aperture problem. An extensive set of representative numerical results is included.
Molecular gas electron distribution function with space and time variation

An approximate, electron energy distribution function, f(/spl epsi/,x,t), is obtained for the case of a slightly ionized gas with inelastic electron-molecule collisions, and for an external electric field with both spatial and temporal variation, E(x,t). This analysis yields an approximate solution for the isotropic leading term of the spherical harmonic expansion of the Boltzmann equation. This result is considered valid when the electric field has a characteristic frequency |/spl omega/| /spl lambda//sub m/, where these parameters are defined as: w(x,t)=(3/2)(/sup /spl part////spl part/t) 1n[IE(x,t)l+/sup kT//e/spl lambda/m], and where v/sub m/ and /spl lambda//sub m/ are respectively the electron-molecule elastic collision frequency and mean free path at thermal energy. There are no other limiting assumptions made about gas mixture composition, cross-section shapes, or electric field space and time behavior. An interesting feature of this analytical distribution function is its explicit dependence on both the magnitude of the field, E(x,t), and its gradients, /spl omega/(x,t) and /spl lambda//sub e/(x,t). Example distribution functions are shown for an idealized N/sub 2/-like gas. These examples include electric fields with ramp or sinusoidal temporal variations, or an exponential spatial decay.
A weak type inequality for non-commutative martingales and applications

We prove a weak-type (1,1) inequality for square functions of non- commutative martingales that are simultaneously bounded in L 2 and L 1 . More precisely, the following non-commutative analogue of a classical result of Burkholder holds: there exists an absolute constant K > 0 such that if M is a semi-finite von Neumann algebra and (Mn) 1=1 is an increasing filtration of von Neumann subalgebras of M then for any given martingale x = (xn) 1=1 that is bounded in L 2 (M) ∩ L 1 (M), adapted to (Mn) 1=1, there exist two martingale difference sequences, a = (an) 1=1 and b = (bn) 1=1 , with dxn = an + bn for every n ≥ 1, 1 X n=1 aan ! 1/2
String Propagation in the Presence of Cosmological Singularities

We study string propagation in a spacetime with positive cosmological constant, which includes a circle whose radius approaches a finite value as |t|??, and goes to zero at t = 0. Near this cosmological singularity, the spacetime looks like 1,1/. In string theory, this spacetime must be extended by including four additional regions, two of which are compact. The other two introduce new asymptotic regions, corresponding to early and late times, respectively. States of quantum fields in this spacetime are defined in the tensor product of the two Hilbert spaces corresponding to the early time asymptotic regions, and the S-matrix describes the evolution of such states to states in the tensor product of the two late time asymptotic regions. We show that string theory provides a unique continuation of wavefunctions past the cosmological singularities, and allows one to compute the S-matrix. The incoming vacuum evolves into an outgoing state with particles. We also discuss instabilities of asymptotically timelike linear dilaton spacetimes, and the question of holography in such spaces. Finally, we briefly comment on the relation of our results to recent discussions of de Sitter space.
Solution to the Ghost Problem in Fourth Order Derivative Theories

We present a solution to the ghost problem in fourth order derivative theories. In particular we study the Pais–Uhlenbeck fourth order oscillator model, a model which serves as a prototype for theories which are based on second plus fourth order derivative actions. Via a Dirac constraint method quantization we construct the appropriate quantum-mechanical Hamiltonian and Hilbert space for the system. We find that while the second-quantized Fock space of the general Pais–Uhlenbeck model does indeed contain the negative norm energy eigenstates which are characteristic of higher derivative theories, in the limit in which we switch off the second order action, such ghost states are found to move off shell, with the spectrum of asymptotic in and out S-matrix states of the pure fourth order theory which results being found to be completely devoid of states with either negative energy or negative norm. We confirm these results by quantizing the Pais–Uhlenbeck theory via path integration and by constructing the associated first-quantized wave mechanics, and show that the disappearance of the would-be ghosts from the energy eigenspectrum in the pure fourth order limit is required by a hidden symmetry that the pure fourth order theory is unexpectedly found to possess. The occurrence of on-shell ghosts is thus seen not to be a shortcoming of pure fourth order theories per se, but rather to be one which only arises when fourth and second order theories are coupled to each other.
Inferences of plasma parameters from coronal hole observations

The temperature in the acceleration region of the solar wind remains one of the most elusive parameters to measure. Knowledge of the temperature as well as its gradient in the inner corona is fundamental for placing constraints on physical mechanisms thought to be responsible for the coronal heating process, as well as for understanding the flow properties of the solar wind. Estimates of the helium abundance is essential for understanding the puzzling behavior of heavier ions in the solar wind. As an illustration of the difficulties and uncertainties involved in the inferences of plasma parameters in the wolar wind acceleration region, The inference of electron temperature and helium abundance will be described. Prospects for future observations will be briefly discussed.
The current non-status of general equilibrium theory

This paper argues that the abandonment of general equilibrium theory by microeconomists was a mistake. It provides counter arguments to two of the reasons for that abandonment—lack of both generality and consistency with methodological individualism in uniqueness and stability analysis of equilibria—and urges microeconomists to refocus some of their attention on it.
Computational complexity of some problems involving congruences on algebras

We prove that several problems concerning congruences on algebras are complete for nondeterministic log-space. These problems are: determining the congruence on a given algebra generated by a set of pairs, and determining whether a given algebra is simple or subdirectly irreducible. We also consider the problem of determining the smallest fully invariant congruence on a given algebra containing a given set of pairs. We prove that this problem is complete for nondeterministic polynomial time.
THE UV-MID-IR SPECTRAL ENERGY DISTRIBUTION OF A z = 1.7 QUASAR HOST GALAXY

We have measured the spectral energy distribution (SED) of the host galaxy of the zs = 1.7 gravitationally lensed quasar SDSS J1004+4112 from 0.44-8.0 μm (0.16-3.0 μm in the rest frame). The large angular extent of the lensed images and their separation from the central galaxy of this cluster lens allows the images to be resolved even with the Spitzer Space Telescope. Based on the SED, the host galaxy is a mixture of relatively old and intermediate age stars with an inferred stellar mass of log(M /M ☉) = 11.09 ± 0.28 and a star-formation rate of yr–1) = 1.21 ± 0.26. Given the estimated black hole mass of M BH 108.6 M ☉ from locally calibrated correlations of black hole masses with line widths and luminosities, the black hole represents a fraction log(M BH/M ) = –2.49 ± 0.28 of the stellar mass and it is radiating at 0.24 ± 0.05 of the Eddington limit. The ratio of the host stellar mass to the black hole mass is only marginally consistent with the locally observed ratio.
Electrochemical Glucose Biosensors

First-generation glucose biosensors relied on the use of the natural oxygen cosubstrate and the production and detection of hydrogen peroxide and were much simpler, especially when miniaturized sensors are concerned. More sophisticated bioelectronic systems for enhancing the electrical response, based on patterned monolayer or multilayer assemblies and organized enzyme networks on solid electrodes, have been developed for contacting GOx with the electrode support. Electrochemical biosensors are well suited for satisfying the needs of personal (home) glucose testing, and the majority of personal blood glucose meters are based on disposable (screen-printed) enzyme electrode test strips, which are mass produced by the thick film (screen-printing) microfabrication technology. In the counter and an additional “baseline” working electrode, various membranes (mesh) are incorporated into the test strips along with surfactants, to provide a uniform sample coverage. Such devices offer considerable promise for obtaining the desired clinical information in a simpler, user-friendly, faster, and cheaper manner compared to traditional assays. Continuous ex-vivo monitoring of blood glucose was proposed in 1974 and the majority of glucose sensors used for in-vivo applications are based on the GOx-catalyzed oxidation of glucose by oxygen. The major factors that play a role in the development of clinically accurate in-vivo glucose sensors include issues related to biocompatibility, miniaturization, long-term stability of the enzyme and transducer, oxygen deficit, short stabilization times, in-vivo calibration, baseline drift, safety, and convenience.
Optimal Saving under Poisson Uncertainty

Abstract This paper studies optimal saving and investment behaviour of a household that can either invest in a riskless or a risky saving technology when risk results from a Poisson process. The focus is on behaviour of households in a general equilibrium setup. Poisson processes are introduced since they allow us to understand and model endogenous cycles jointly with long-run growth. It turns out that a very simple, intuitive and tractable characterization of equilibrium is possible. Journal of Economic Literature Classification Numbers: C61, O33, O41.
Demographic Trends and Pension System in Italy: an Assessment of 1990s Reforms

In the last decade the Italian pension system underwent many changes. The process has started in 1992 with three major reform laws (passed in 1992, 1995 and 1997), supplemented by many other minor changes. Among the innovations introduced in the pay-as-you-go social security system, the most important one is the more explicit link between pensions and contributions, and pensions and life expectancy at retirement. The purpose of this paper is to provide an assessment of both the short-term and the long-term effects of the social secu- rity reforms on pension expenditure. Notwithstanding the slowdown in the growth rate of the pension expenditure/GDP ratio, the measures adopted so far will not be sufficient to eliminate the existing social security deficit in the next decades, par- ticularly under the assumption of moderate economic performance and rapid population ageing. Reducing public pension expenditure requires the completion of the 1995 reform, a more rapid move towards a multi-pillar pension scheme, and the implementation of the much needed growth-enhancing structural reforms.
Dispersion in Disks

We present three new approximation algorithms with improved constant ratios for selecting n points in n disks such that the minimum pairwise distance among the points is maximized. A very simple O(nlog n)-time algorithm with ratio 0.511 for disjoint unit disks. An LP-based algorithm with ratio 0.707 for disjoint disks of arbitrary radii that uses a linear number of variables and constraints, and runs in polynomial time. A hybrid algorithm with ratio either 0.4487 or 0.4674 for (not necessarily disjoint) unit disks that uses an algorithm of Cabello in combination with either the simple O(nlog n)-time algorithm or the LP-based algorithm. The LP algorithm can be extended for disjoint balls of arbitrary radii in ℝ d , for any (fixed) dimension d, while preserving the features of the planar algorithm. The algorithm introduces a novel technique which combines linear programming and projections for approximating Euclidean distances. The previous best approximation ratio for dispersion in disjoint disks, even when all disks have the same radius, was 1/2. Our results give a positive answer to an open question raised by Cabello, who asked whether the ratio 1/2 could be improved.
Immigrant employment through the Great Recession: Individual characteristics and metropolitan contexts

Abstract Immigrants continue to settle in metropolitan areas across the United States and bring significant changes to various urban labor markets. Using American Community Survey (ACS) data for 2007 and 2011, we trace the employment outcomes of immigrants compared to native-born workers before and after the recent Great Recession across the 100 largest metropolitan areas and examine individual-level and metropolitan-level factors that shape their employment outcomes. We find that low-skilled workers in general and immigrants without English proficiency and those who are new entrants or earliest arrivals are harder hit in the recession. Latino immigrants and black workers fare worse in areas with high immigrant concentration. Latino immigrants experience employment gains, however, in the South, large urban economies, as well as new immigrant gateways. Asian immigrants see declines in employment likelihood in areas with a large construction sector, while areas with a large trade sector hurt native-born white workers.
Causal properties of free string field theory

Abstract This paper examines the causal structure of the commutator of two string fields, in free light-cone string field theory. By treating the commutator as a distribution on infinite dimensional loop space, it is shown that the commutator vanishes when ∫d σ ( δX ( σ )) 2