cssi/SciSciGPT-SciSciNet huggingface dataset:
Robust feedback control of flow-induced structural radiation of sound

The paper presents the robust multivariable control of noise radiation from panels driven by turbulent flow. The controlled inputs are point forces to the panel and the feedback signals are panel accelerations. Collocated actuator/sensor locations on the panel are chosen such that vibration control will lead to a reduction in the radiated sound pressure levels. The multivariable controller is realized though a sequential loop closure approach. Each controller is designed in the frequency domain where the impact of system uncertainty and closed-loop sensitivity can be analyzed. The proposed frequency domain approach will also facilitate the design of feedback controllers that employ the natural dynamics of the panel for noise control purposes. The proposed design technique is experimentally validated on a panel subjected to turbulent flow in a quiet wind tunnel. Active control of the sound radiation was achieved at frequencies as high as 1000 Hz. Sound pressure level reductions of as much as 15 dB were achieved at the resonant frequencies of the panel modes. Overall reductions over the 100-1000 Hz band were approximately 5 dB.
Fast Recovery From Link Failures in Ethernet Networks

Fast-recovery from link failures is a well-studied topic in IP networks. Employing fast-recovery in Ethernet networks is complicated as the forwarding is based on destination MAC addresses, which do not have the hierarchical nature similar to those exhibited in Layer 3 in the form of IP-prefixes. Moreover, switches employ backward learning to populate the forwarding table entries. Thus, any fast recovery mechanism in Ethernet networks must be based on undirected spanning trees if backward learning is to be retained. In this paper, we develop three alternatives for achieving fast recovery from single link failures in Ethernet networks. All three approaches provide guaranteed recovery from single link failures. The approaches differ in the technologies required for achieving fast recovery, namely VLAN rewrite or mac-in-mac encapsulation or both. We study the performance of the approaches developed on five different networks.
Tone-dependent error diffusion

We present an enhanced error diffusion halftoning algorithm for which the filter weights and the quantizer thresholds vary depending on input pixel value. The weights and thresholds are optimized based on a human visual system model. Based on an analysis of the edge behavior, a tone dependent threshold is designed to reduce edge effects and start-up delay. We also propose an error diffusion system with parallel scan that uses variable weight locations to reduce worms.
A RELATION BETWEEN SUPERMASSIVE BLACK HOLE MASS AND QUASAR METALLICITY

We analyze spectra for a large sample of 578 active galactic nuclei to examine the relationships between broad emission line properties and central supermassive black hole (SMBH) mass. We estimate SMBH masses by applying the virial theorem to the C iv � 1549 broad emission line. Although the FWHMs of C iv and Happear nearly unrelated in individual objects, these FWHMs are well correlated when averaged over subsamples in our database. Therefore, the lines are equally valid indicators of the average SMBH mass in quasar samples. Our sample spans 5 orders of magnitude in SMBH mass, 6 orders of magnitude in luminosity, and a redshift range of 0 � z � 5. Most lines diminish in equivalent width with increasing black hole mass (the usual '' Baldwin effect ''), and there are no trends with redshift. Recent studies indicate that there is a relationship between SMBH mass and the overall bulge/spheroidal component mass of the sur- rounding galaxy. This relation, together with the well-known mass-metallicity relationship among galaxies, predicts a relationship between SMBH mass and quasar metallicity. We estimate the metallicity in the broad emission line region by comparing several line ratios involving nitrogen to theoretical predictions. We find that the data are consistent with a trend between SMBH mass and metallicity, with some line ratios indicating a very strong trend, but the uncertainties in several other important line ratios are too large to confirm or test this correlation. Subject headings: galaxies: abundances — galaxies: active — galaxies: formation — quasars: emission lines
False Modesty: When Disclosing Good News Looks Bad

Abstract Is it always wise to disclose good news? Using a new statistical dominance condition, we show that if the receiver has any private receiver information then the weakest senders with good news gain the most from boasting about it. Hence the act of disclosing good news can paradoxically make the sender look bad. Nondisclosure by some or all senders is an equilibrium if standards for the news are sufficiently easy or if prior expectations without the news are sufficiently favorable. Full disclosure is the unique equilibrium if standards are sufficiently difficult or sufficiently fine, or if prior expectations are sufficiently unfavorable. Since the sender has a legitimate fear of looking overly anxious to reveal good news, mandating that the sender disclose the news can help the sender. The model’s predictions are consistent with when faculty avoid using titles such as “Dr.” or “Professor” in voicemail greetings and course syllabi.
Shaped pupil design for the Gemini Planet Imager

The Gemini Planet Imager is an instrument designed for the Gemini South Telescope to image young Jupiter-mass planets in the infrared. To achieve the high contrast needed for this, it employs an apodized pupil Lyot coronagraph (APLC) to remove most of the starlight. Current designs use a partially transmitting apodizer in the pupil; we examine the use of binary apodizations in the form of star-shaped pupils and present a design that could achieve comparable performance, along with a series of design guidelines for creating shaped pupil versions of APLCs in other systems.
In Vivo Gene Transfer of Endothelial Nitric Oxide Synthase to Carotid Arteries From Hypercholesterolemic Rabbits Enhances Endothelium-Dependent Relaxations

Background and Purpose —Hypercholesterolemia is associated with abnormal endothelium-dependent vasorelaxation due to decreased nitric oxide bioavailability. Our aim was to examine the effect of adenovirus-mediated gene transfer of endothelial nitric oxide synthase (eNOS) to the hypercholesterolemic rabbit carotid artery in vivo. In addition, we examined whether adenovirus-mediated gene transfer was associated with vascular dysfunction. Methods —Rabbits were fed a 1% cholesterol diet for 4 weeks followed by a 0.5% cholesterol diet for 6 weeks. Vascular reactivity was assessed in nontransduced carotid arteries from chow- and cholesterol-fed animals. In addition, carotid arteries were surgically isolated, and 2 separate doses of adenoviral vectors encoding eNOS or β-galactosidase (AdβGal) on the contralateral side were delivered to the lumen (1×1010 and 5×1010 pfu/mL). Results —Abnormal acetylcholine-mediated endothelium-dependent vasorelaxation was detected in the carotid artery from cholesterol-fed animals, whereas responses to calcium ionophore A23187 and diethylamine NONOate were normal. Vascular reactivity was similar in nontransduced and AdβGal-transduced hypercholesterolemic vessels. In vessels transduced with eNOS, transgene expression was demonstrated by immunostaining in both the endothelium and the adventitia and by Western blot analysis. High-dose but not low-dose eNOS gene transfer enhanced endothelium-dependent relaxation in vessels from cholesterol-fed rabbits. Conclusions —Adenovirus-mediated gene transfer of eNOS to carotid arteries of cholesterol-fed animals improves endothelium-dependent relaxation when an optimal viral titer is administered.
Estimation of Strong Ground Motions from Hypothetical Earthquakes on the Cascadia Subduction Zone, Pacific Northwest

Strong ground motions are estimated for the Pacific Northwest assuming that large shallow earthquakes, similar to those experienced in southern Chile, southwestern Japan, and Colombia, may also occur on the Cascadia subduction zone. Fifty-six strong motion recordings for twenty-five subduction earthquakes of M s ≥ 7.0 are used to estimate the response spectra that may result from earthquakes M w < 8 1/4. Large variations in observed ground motion levels are noted for a given site distance and earthquake magnitude. When compared with motions that have been observed in the western United States, large subduction zone earthquakes produce relatively large ground motions at surprisingly large distances. An earthquake similar to the 22 May 1960 Chilean earthquake (M w 9.5) is the largest event that is considered to be plausible for the Cascadia subduction zone. This event has a moment which is two orders of magnitude larger than the largest earthquake for which we have strong motion records. The empirical Green’s function technique is used to synthesize strong ground motions for such giant earthquakes. Observed teleseismic P-waveforms from giant earthquakes are also modeled using the empirical Green’s function technique in order to constrain model parameters. The teleseismic modeling in the period range of 1.0 to 50 sec strongly suggests that fewer Green’s functions should be randomly summed than is required to match the long-period moments of giant earthquakes. It appears that a large portion of the moment associated with giant earthquakes occurs at very long periods that are outside the frequency band of interest for strong ground motions. Nevertheless, the occurrence of a giant earthquake in the Pacific Northwest may produce quite strong shaking over a very large region.
The ethnicity distraction ? political credibility and partisan preferences in Africa

Much of the research on ethnicity, development and conflict implicitly assumes that ethnic groups act collectively in pursuit of their interests. Collective political action is typically facilitated by political parties able to make credible commitments to pursue group interests. Other work, however, emphasizes the lack of political credibility as a source of adverse development outcomes. Evidence presented here uses partisan preferences across 16 Sub-Saharan African countries to distinguish these positions. The evidence is inconsistent with the credibility of party commitments to pursue collective ethnic interests: ethnic clustering of political support is less widespread than expected; members of clustered ethnic groups exhibit high rates of partisan disinterest and are only slightly more likely to express a partisan preference; and partisan preferences are more affected by factors, such as gift-giving, often associated with low political credibility. These findings emphasize the importance of looking beyond ethnicity in analyses of economic development.
Sub-Wavelength Grating Induced Wavefront Aberrations: A Case Study

The on-axis polarization aberration function of a one-dimensional sub-wavelength grating anti-reflection coating on a f/1.7 lens surface is analyzed. 0.02 waves of astigmatism are induced and the retardance aberration (astigmatism+defocus) is less than 0.02 waves.
ENTREPRENEURSHIP IN TRANSITIONAL ECONOMIES: REVIEW AND INTEGRATION OF TWO DECADES OF RESEARCH

This review maps research on entrepreneurship in transitional economies since the start of institutional reforms. Data came from 129 academic journal articles published between 1990 and 2009. 62 articles reported research on macro (country) level, discussing the nature and speed of reform, credit constraints, assistance programs and the role of small business for economic development. 67 articles studied micro (firm) level factors, but only 14 of them employed data analytical methods to study what explains entrepreneurial success, suggesting a role for networking, industry experience and entrepreneurial orientation. We suggest more research on understanding the context of entrepreneurship, with a special focus on the informal institutional environment and industry structure. Also, future research can explore topics such as strategic agendas, opportunity identification and entrepreneurial cognition, which have been rare to date. We particularly emphasize the need for rigorous and replicable large-scale empirical studies.
The Discrete Memoryless Multiple Access Channel with Confidential Messages

A multiple-access channel is considered in which messages from one encoder are confidential. Confidential messages are to be transmitted with perfect secrecy, as measured by equivocation at the other encoder. The upper bounds and the achievable rates for this communication situation are determined.
Empirical Constraints on the Oblateness of an Exoplanet

We show that the gas giant exoplanet HD 189733b is less oblate than Saturn, based on Spitzer Space Telescope photometry of seven transits. The observable manifestations of oblateness would have been slight anomalies during the ingress and egress phases, as well as variations in the transit depth due to spin precession. Our nondetection of these effects gives the first empirical constraints on the shape of an exoplanet. The results are consistent with the theoretical expectation that the planetary rotation period and orbital period are synchronized, in which case the oblateness would be an order of magnitude smaller than our upper limits. Conversely, if HD 189733b is assumed to be in a synchronous, zero-obliquity state, then the data give an upper bound on the quadrupole moment of the planet (J 2 < 0.068 with 95% confidence) that is too weak to constrain the interior structure of the planet. An Appendix describes a fast algorithm for computing the transit light curve of an oblate planet, which was necessary for our analysis.
Environment and security

▪ Abstract A broadening research program focused on environment and security emerged over the past 30 years. But the meaning and operationalization of environment and security have been an implicit and increasingly explicit part of the scholarly debate. Approaches range from the more specific focus on the linkages between environmental change and violent (deadly) conflict, the possible role of environmental conservation, cooperation, and collaboration in promoting peace, and the broader focus on potential relationships between environmental change and human security (understood as freedom from both violent conflict and physical want). In addition to the different conceptions of environment and security, the type and direction of causal relationships among different factors continue to be a focus of research. With respect to the environment and violent conflict, which constitute the largest explicit research stream on environment and security, the debate has centered on whether and why environmental scarci...
Permeability–porosity relationships of subduction zone sediments

Abstract Permeability–porosity relationships for sediments from the northern Barbados, Costa Rica, Nankai, and Peru subduction zones were examined based on sediment type, grain size distribution, and general mechanical and chemical compaction history. Greater correlation was observed between permeability and porosity in siliciclastic sediments, diatom oozes, and nannofossil chalks than in nannofossil oozes. For siliciclastic sediments, grouping of sediments by percentage of clay-sized material yields relationships that are generally consistent with results from other marine settings and suggests decreasing permeability as percentage of clay-sized material increases. Correction of measured porosities for smectite content improved the correlation of permeability–porosity relationships for siliciclastic sediments and diatom oozes. The relationship between permeability and porosity for diatom oozes is very similar to the relationship in siliciclastic sediments, and permeabilities of both sediment types are related to the amount of clay-size particles. In contrast, nannofossil oozes have higher permeability values by 1.5 orders of magnitude than siliciclastic sediments of the same porosity and show poor correlation between permeability and porosity. More indurated calcareous sediments, nannofossil chalks, overlap siliciclastic permeabilities at the lower end of their measured permeability range, suggesting similar consolidation patterns at depth. Thus, the lack of correlation between permeability and porosity for nannofossil oozes is likely related to variations in mechanical and chemical compaction at shallow depths. This study provides the foundation for a much-needed global database with fundamental properties that relate to permeability in marine settings. Further progress in delineating controls on permeability requires additional carefully documented permeability measurements on well-characterized samples.
THE IMPACT OF FINANCIAL TRANSACTIONS TAXES ON MONEY DEMAND IN COLOMBIA

Some countries in Latin America have introduced a tax on bank withdrawals in order to increase revenue. The debit tax has usually been levied in periods of economic turbulence. This paper analyzes the effects of such a tax on real cash holdings and on balances of different types of bank accounts in Colombia. The paper analyzes data for the period 1994 to 2007 and then verifies the robustness of the model using only the data from 2000 to 2007, thereby eliminating the economic crisis of the late 1990s. The results show that even though the tax caused a decrease in checking account balances, the changes produced in total balances of real cash after 2001 cannot be attributed to the debit tax. However, an increase in the rate of growth of savings account balances can be attributed to it, suggesting a substitution from checking toward savings accounts. JEL clasification : G21, H20, N26, E41
Dual frequency correlation radar measurements of the height statistics of ocean waves

A radar technique has been developed for measuring the statistical height properties of a random rough surface. This method is being applied to the problem of measuring the significant wave height and probability density function of ocean waves from an aircraft or spacecraft. Earlier theoretical and laboratory results have been extended to define the requirements and performance limitations of flight systems. Some details of the current airborne radar system are discussed and results obtained on several experimental missions are presented and interpreted.
Spin-driven tidal pumping: tidally driven changes in planetary spin coupled with secular interactions between planets

In a multiplanet system, tides acting on the inner planet can significantly affect the orbital evolution of the entire system. While tides usually damp eccentricities, a novel mechanism identified by Correia et al. (Astrophys J Lett 744, article id. L23, 2012) tends to raise eccentricities as a result of the tides’ effect on the inner planet’s rotation. Our analytical description of this spin-driven tidal (SDT) effect shows that, while the inner planet’s eccentricity undergoes pumping, the process is more completely described by an exchange of strength between the two eigenmodes of the dynamical system. Our analysis allows derivation of criteria for two-planet coplanar systems where the SDT effect can reverse tidal damping, and may preclude the effect’s being significant for realistic systems. For the specific case quantified by Correia et al., the effect is strong because of the large adopted tidal time lag, which may not be appropriate for the assumed Saturn-like inner planet. On the other hand, the effective \(Q\) for any given planet in exotic circumstances is very uncertain, so the SDT effect could play a role in planetary evolution.
Androstenediol Regulates Systemic Resistance against Lethal Infections in Mice

We previously reported that subcutaneous injection of DHEA (5-androsten-3 β-ol-17-one, dehydroepiandrosterone) protected mice from lethal infection. This included both a lethal herpes virus type 2 encephalitis and a lethal systemic coxsackievirus B 4 (CB 4) infection. Androstenediol (5-andros-ten-3 β-17 β-diol, AED), a metabolic product of DHEA is up to 100×more effective in regulating systemic resistance against lethal infection with CB 4 than its precursor DHEA. Compared to DHEA, treatment with AED was markedly superior in protecting mice against virus induced myocardiopathy, pancreopathy, and mortality. In addition to its protective effect, AED but not DHEA, induced a 3–4 fold proliferation of the spleen and thymus in virus infected animals; this effect of AED was only seen above a certain threshold dose. Neither steroid, however, has shown any significant direct antiviral effect in vitro; similarly, virus tissues titers in vivo are not affected by the hormones. Additionally, both DHEA and AED protected against a lethal infection withEnterococcus faecalis. These observations demonstrate that the steroid hormones DHEA and AED provide a novel approach for prevention and protection of the host from a variety of infectious diseases.
Use of Local X-Ray Computerized Tomography for High-Resolution, Region-of-Interest Inspection of Large Ceramic Components for Engines

Reliability continues to be an issue in ceramic components for high-temperature, high-wear applications in advanced engine designs. Recently, high-resolution, three-dimensional, X-ray computerized tomography (XRCT) has been shown to be invaluable for inspecting relatively small components. However, the time and system capacity required to collect complete high-resolution data for large ceramic objects is often prohibitive. When only the critical regions of a large component need be inspected with high resolution, region-of-interest XRCT is a viable alternative. With local XRCT methods used on data taken through only the critical area, it is possible to reconstruct flat, ``edge-enhanced`` images in which density differences are clearly delineated. We present XRCT results from local scans of critical regions in a large, pressure-slip-cast, Si{sub 3}N{sub 4} turbine rotor and two Si{sub 3}N{sub 4} test phantoms. We also illustrate how the method can be extended to larger assemblies of ceramic components.
Raman and Infrared Thermometry for Microsystems

This paper compares measurements made by Raman and infrared thermometry on a SOI (silicon on insulator) bent-beam thermal microactuator. Both techniques are noncontact and used to experimentally measure temperatures along the legs and on the shuttle of the thermal microactuators. Raman thermometry offers micron spatial resolution and measurement uncertainties of {+-}10 K; however, typical data collection times are a minute per location leading to measurement times on the order of hours for a complete temperature profile. Infrared thermometry obtains a full-field measurement so the data collection time is much shorter; however, the spatial resolution is lower and calibrating the system for quantitative measurements is challenging. By obtaining thermal profiles on the same SOI thermal microactuator, the relative strengths and weaknesses of the two techniques are assessed.
Synthesis of the first α-fluoro-phosphotyrosyl mimetic

Abstract The diastereoselective preparation of (2S)‐2‐fluoro‐4‐[[bis(1,1‐dimethylethoxy)phosphinyl]methyl] benzenepropanoic acid (5) is presented as new phosphotyrosyl (pTyr) mimetic suitably protected for incorporation into peptides. Synthesis of 5 utilized electrophilic fluorination under chiral induction provided by the commercially available Evans auxiliary, (S)‐(+)‐4‐phenyl‐2‐oxazolidinone. In order to demonstrate its synthetic utility, analogue 5 was employed to prepare a signal transduction‐directed tripeptide. The design considerations for this peptide and its preliminary biological evaluation are included.
ELECTROMAGNETIC TRANSITIONS WITH EFFECTIVE OPERATORS

In the no-core shell model formalism we compute effective one- and two-body operators, using the Lee–Suzuki procedure within the two-body cluster approximation. We evaluate the validity of the latter through calculations in reduced model spaces. In particular, we test the results for the two-body system and find that indeed the effective operators in the reduced space reproduce the expectation values or transition strengths computed in the full space. On the other hand, the renormalization for operators in the case of 6Li is very weak, suggesting the need for higher-body clusters in computing the effective interaction.
Local and global well-posedness for aggregation equations and Patlak–Keller–Segel models with degenerate diffusion

Recently, there has been a wide interest in the study of aggregation equations and Patlak–Keller–Segel (PKS) models for chemotaxis with degenerate diffusion. The focus of this paper is the unification and generalization of the well-posedness theory of these models. We prove local well-posedness on bounded domains for dimensions d ≥ 2 and in all of space for d ≥ 3, the uniqueness being a result previously not known for PKS with degenerate diffusion. We generalize the notion of criticality for PKS and show that subcritical problems are globally well-posed. For a fairly general class of problems, we prove the existence of a critical mass which sharply divides the possibility of finite time blow-up and global existence. Moreover, we compute the critical mass for fully general problems and show that solutions with smaller mass exists globally. For a class of supercritical problems we prove finite time blow-up is possible for initial data of arbitrary mass.
Antifungal Susceptibility Testing in Teaching Hospitals

BACKGROUND:An assessment of antifungal susceptibility testing (AST) has not been conducted since the introduction of the National Committee for Clinical Laboratory Standards (NCCLS) M27-A document.OBJECTIVE:To determine AST practices in teaching hospitals.METHODS:A questionnaire was mailed to the heads of 386 randomly assigned microbiology departments from teaching hospitals identified through the 2000 American Hospital Association Guide. Identifiers were used to delineate responders from nonresponders. A reminder letter was mailed 3 weeks after the initial mailing to all nonresponders. The hospital bed-size and number of inpatient days for respondents were obtained through the American Hospital Directory.RESULTS:The questionnaire was returned by 171 (44.3%) institutions. The total and median (range) number of candida isolates were 137 088 and 8.5 (1–145)/1000 inpatient days for the year 2000, respectively. Approximately 1% (1300) of candida isolates, from predominantly blood specimens, underwent AST. AST...
Chemical genetics: exploring the role of the proteasome in cell biology using natural products and other small molecule proteasome inhibitors.

In the era of systemic proteomics, temporal and spatial control of protein functions has become very important in the investigation of complex biological processes in vivo. While traditional genetic manipulations have provided a powerful tool to study protein function, these applications are limited by the possibility that some mutant phenotypes may be due to compensatory responses that occur during development. In addition, gene knockout models that are embryonic lethal are not amenable to study disease processes that occur in the adult animal. Moreover, the inhibition of the target gene’s function is often irreversible, and thus, the desired biological effect(s) cannot be readily regulated. This makes it difficult to dissect the precise role of proteins in complex signaling pathways. Recently, small interfering RNA (siRNAa) has been widely used to modulate protein function at the RNA level.1 However, this technique offers limited temporal control of gene expression. Difficulties with the nonspecificity and delivery of siRNAs have also been major concerns. The use of small-molecule probes is one way to complement these genetic approaches. Most biologically active small molecules including natural products exert their activities via inhibition of specific biological processes. In comparison to the classical genetic approach, this small molecule approach easily affords more temporal and spatial control of targeted biological events. A small molecule approach, being complementary to the classical genetic approach, is thus fittingly dubbed “chemical genetics”.2 Although many areas of biology have benefited from the chemical genetics approach, few have been more broadly and significantly impacted than the biology and biochemistry of the proteasome.
Facile production and cyclizations of amidyl radicals

Abstract Amides were converted via imidoyl chlorides into N -hydroxypyridine-2-thione imidate esters that were precursors for amidyl radicals; amidyl radicals containing δ,ϵ-unsaturated cyclized in a 5- exo fashion.
Inelastic Asymmetric Buckling of Ring-Stiffened Cylindrical Shells under External Pressure

A variational principle and associated criteria on bifurcation and stability of elastic-plastic solids, which are expressed in terms of Lagrangian variables, are described. The principle is employed to study the effects of prebuckling deformation and yield surface corners on the inelastic asymmetric buckling of a ring-stiffened cylindrical shell under external pressure. The shell is made of a work-hardening material having incremental type constitutive relationships associated with either Mises' yield surface or a yield surface with corners. An incremental Rayleigh-Ritz numerical method is employed to determine the nonlinear deformation process and asymmetric bifurcation pressure. Numerical results are obtained and compared with available experimental results
The toroidal obscuration of active galactic nuclei

Observations give strong support for the unification scheme of active galactic nuclei. The scheme is premised on toroidal obscuration of the central engine by dusty clouds that are individually very optically thick. These lectures summarize the torus properties, describe the handling and implications of its clumpy nature and present speculations about its dynamic origin.
Effect of magnet sorting using a simple resonance cancellation method on the RMS orbit distortion at the APS injector synchrotron

The Advanced Photon Source injector synchrotron is a 7 GeV positron machine with a standard alternating gradient lattice. The calculated effect of dipole magnet strength errors on the orbit distortion, simulated by Monte Carlo, was reduced by sorting pairs of magnets having the closest simulated measured strengths to reduce the driving term of the integer resonance nearest the operating point. This method resulted in a factor of four average reduction in the RMS orbit distortion when all 68 magnets were sorted at once. The simulated effect of magnet measurement experimental resolution was found to limit the actual improvement. The /spl beta/-beat factors were similarly reduced by sorting the quadrupole magnets according to their gradients. >
Improved Algorithms for Parsing ESLTAGs: A Grammatical Model Suitable for RNA Pseudoknots

Formal grammars have been employed in biology to solve various important problems. In particular, grammars have been used to model and predict RNA structures. Two such grammars are Simple Linear Tree Adjoining Grammars (SLTAGs) and Extended SLTAGs (ESLTAGs). Performances of techniques that employ grammatical formalisms critically depend on the efficiency of the underlying parsing algorithms. In this paper, we present efficient algorithms for parsing SLTAGs and ESLTAGs. Our algorithm for SLTAGs parsing takes O({\rm min} \{m,n^4\} ) time and O({\rm min} \{m,n^4\} ) space, where m is the number of entries that will ever be made in the matrix M (that is normally used by TAG parsing algorithms). Our algorithm for ESLTAGs parsing takes O(n{\rm min} \{m,n^4\} ) time and O({\rm min} \{m,n^4\} ) space. We show that these algorithms perform better, in practice, than the algorithms of Uemura et al. [21].
The representative jury requirement: Jury representativeness and cross sectional participation from the beginning to the end of the jury selection process

The paper specifically addresses the many ways in which the facially neutral procedures actually fail to secure representative jury pools. Although the Sixth Amendment's fair cross‐section requirement forbids systematic discrimination in the creation of the jury venire and panel, it does not guarantee that the criminal jury will in fact reflect an accurate cross‐section of the community. As a result, not only does the Court fail to focus on nonlegally recognized screening mechanisms and factors such as exemptions, excuses, failure to followup jurors, etc., may affect jury representativeness, but also the Court never examined cross‐sectional representation at the entirety of the jury selection processes, except jury panels and final juries. The first section of this paper presents a brief overview of the constitutional law impacting impartial juries, especially addressing the fair cross‐section doctrine that is the focus of contemporary jury selection procedures. In providing empirical and systematic compa...
Space-time codes for wireless optical communications

A space-time channel coding technique is presented for overcoming turbulence-induced fading in an atmospheric optical heterodyne communication system that uses multiple transmit and receive apertures. In particular, a design criterion for minimizing the pairwise probability of codeword error in a space-time code (STC) is developed from a central limit theorem approximation. This design criterion maximizes the mean-to-standard-deviation ratio of the received energy difference between codewords. It leads to STCs that are a subset of the previously reported STCs for Rayleigh channels, namely those created from orthogonal designs. This approach also extends to other fading channels with independent, zero-mean path gains. Consequently, for large numbers of transmit and receive antennas, STCs created from orthogonal designs minimize the pairwise codeword error probability for this larger class of fading channels.
Design Methods for Current Source Inverter/Induction Motor Drive Systems

A current source inverter combined with a controlled slip induction motor is a reliable and rugged ac drive system. The majority of the inverters in use today are the voltage source type using auxiliary impulse commutation. However, recent advances in SCR blocking voltage capability are making the complementary impulse commutated current source inverter a viable competitor
Postprocessing of recognized strings using nonstationary Markovian models

This paper presents nonstationary Markovian models and their application to recognition of strings of tokens. Domain specific knowledge is brought to bear on the application of recognizing zip codes in the US mailstream by the use of postal directory files. These files provide a wealth of information on the delivery points (mailstops) corresponding to each zip code. This data feeds into the models as n-grams, statistics that are integrated with recognition scores of digit images. An especially interesting facet of the model is its ability to excite and inhibit certain positions in the n-grams leading to the familiar area of Markov random fields. We empirically illustrate the success of Markovian modeling in postprocessing applications of string recognition. We present the recognition accuracy of the different models on a set of 20000 zip codes. The performance is superior to the present system which ignores all contextual information and simply relies on the recognition scores of the digit recognizers.
An apparatus for pseudo-deterministic testing

In this paper we propose a new apparatus for embedding deterministic patterns in pseudo-random sequences, with application to at-speed BIST. We employ an arbitrary length Shift Register driven by a LFSR (LFSR/SR) with the size of the LFSR dependent only on the number of care bits in any test vector. We provide an efficient method to compute positions of bit-patterns at arbitrarily chosen tap configurations in the LFSR/SR sequence. Hence, one can make an optimal choice of test segments (seeds) while taking inherent advantage of don't care bits in test vectors, say corresponding to random pattern resistant faults. The length of the LFSR/SR can be arbitrarily increased to feed several interconnected logic blocks such that all the care bits of any deterministic test vector can be predictably generated without compromising computational efficiency.
Analysis of the multi-phase copying garbage collection algorithm

The multi-phase copying garbage collection was designed to avoid the need for large amount of reserved memory usually required for the copying types of garbage collection algorithms. The collection is performed in multiple phases using the available free memory. This paper proves that the number of phases depends on the size of the reserved memory and the ratio of the garbage and accessible objects. The performance of the implemented algorithm is tested in a fine-grained parallel Prolog system. We find that reserving only 10% of memory for garbage collection is sufficient for good performance in practice. Additionally, an improvement of the generic algorithm specifically for the tested parallel Prolog system is described.
On orbits of order ideals of minuscule posets

An action on order ideals of posets considered by Fon-Der-Flaass is analyzed in the case of posets arising from minuscule representations of complex simple Lie algebras. For these minuscule posets, it is shown that the Fon-Der-Flaass action exhibits the cyclic sieving phenomenon, as defined by Reiner, Stanton, and White. A uniform proof is given by investigation of a bijection due to Stembridge between order ideals of minuscule posets and fully commutative Weyl group elements. This bijection is proven to be equivariant with respect to a conjugate of the Fon-Der-Flaass action and an arbitrary Coxeter element. If P is a minuscule poset, it is shown that the Fon-Der-Flaass action on order ideals of the Cartesian product P×[2] also exhibits the cyclic sieving phenomenon, only the proof is by appeal to the classification of minuscule posets and is not uniform.
Novel, customizable scoring functions, parameterized using N-PLS, for structure-based drug discovery.

The ability to accurately predict biological affinity on the basis of in silico docking to a protein target remains a challenging goal in the CADD arena. Typically, “standard” scoring functions have been employed that use the calculated docking result and a set of empirical parameters to calculate a predicted binding affinity. To improve on this, we are exploring novel strategies for rapidly developing and tuning “customized” scoring functions tailored to a specific need. In the present work, three such customized scoring functions were developed using a set of 129 high-resolution protein−ligand crystal structures with measured Ki values. The functions were parametrized using N-PLS (N-way partial least squares), a multivariate technique well-known in the 3D quantitative structure−activity relationship field. A modest correlation between observed and calculated pKi values using a standard scoring function (r2 = 0.5) could be improved to 0.8 when a customized scoring function was applied. To mimic a more re...
L-functions of symmetric powers of Kloosterman sums (unit root L-functions and p-adic estimates)

The L-function of symmetric powers of classical Kloosterman sums is a polynomial whose degree is now known, as well as the complex absolute values of the roots. In this paper, we provide estimates for the p-adic absolute values of these roots. Our method is indirect. We first develop a Dwork-type p-adic cohomology theory for the two-variable infinite symmetric power L-function associated to the Kloosterman family, and then study p-adic estimates of the eigenvalues of Frobenius. A continuity argument then provides the desired p-adic estimates.
A New Asymptotic Theory for Heteroskedasticity-Autocorrelation Robust Tests

A new …rst-order asymptotic theory for heteroskedasticity-autocorrelation (HAC) robust tests based on nonparametric covariance matrix estimators is developed. The bandwidth of the covariance matrix estimator is modeled as a …xed proportion of the sample size. This leads to a distribution theory for HAC robust tests that explicitly captures the choice of bandwidth and kernel. This contrasts with the traditional asymptotics (where the bandwidth increases slower than the sample size) where the asymptotic distributions of HAC robust tests do not depend on the bandwidth or kernel. Finite sample simulations show that the new approach is more accurate than the traditional asymptotics. The impact of bandwidth and kernel choice on size and power of t-tests is analyzed. Smaller bandwidths lead to tests with higher power but greater size distortions and large bandwidths lead to tests with lower power but less size distortions. Size distortions across bandwidths increase as the serial correlation in the data becomes stronger. Overall, the results clearly indicate that for bandwidth and kernel choice
CREDENCE GOODS MARKETS WITH CONSCIENTIOUS AND SELFISH EXPERTS

I study credence goods markets when there are both selfish and conscientious experts. The selfish expert is a profit maximizer. The conscientious expert wants to maximize profit and repair the consumer's problem. There are two classes of equilibria: uniform-price equilibria and nonuniform-price equilibria. A consumer cannot infer the expert's type from his price list in a uniform-price equilibrium but can do that in a nonuniform-price equilibrium. When the fraction of the conscientious expert is small, the selfish expert will be honest about the severity of the consumer's problem. When the fraction of the conscientious expert is large, the selfish expert will cheat the consumer; overcharging the consumer whenever he offers to repair the problem. Finally, more conscientious experts may result in a larger social loss. When the fraction of the conscientious expert is close to one of the two extremes, 0 and 1, more conscientious experts will result in smaller social loss. When the fraction of the conscientious expert is in a middle range, more conscientious experts may result in a larger social loss.
The structure and spectrum of Heisenberg odometers

Odometer actions of discrete, finitely generated and residually finite groups G have been defined by Cortez and Petite. In this paper we focus on the case where G is the discrete Heisenberg group. We prove a structure theorem for finite index subgroups of the Heisenberg group based on their geometry when they are considered as subsets of Z3. We use this structure theorem to provide a classification of Heisenberg odometers and we construct examples of each class. In order to construct some of the examples we also provide necessary and sufficient conditions for a Zd odometer to be a product odometer as defined by Cortez. It follows from work of Mackey that all such actions have discrete spectrum. Here we provide a different proof of this fact for general G odometers which allows us to identify explicitly those representations of the Heisenberg group which appear in the spectral decomposition of a given Heisenberg odometer.
Upgrades to the DARHT second axis induction cells

The dual-axis radiographic hydrodynamics test (DARHT) facility will employ two perpendicular electron Linear Induction Accelerators to produce intense, bremsstrahlung X-ray pulses for flash radiography. The second axis, DARHT II, features a 2.5-MeV injector and a 15.5-MeV, 2-kA, 1.6-microsecond accelerator consisting of 74 induction cells and drivers. Major induction cell components include high flux swing magnetic material (Metglas 2605SC) and a Mycalextrade insulator. The cell drivers are pulse forming networks (PFNs). The DARHT II accelerator cells have undergone a series of test and modeling efforts to fully understand their operational parameters. These R&D efforts identified problems in the original cell design and means to upgrade the design, performance and reliability of the linear induction cells. Physical changes in the cell oil region, the cell vacuum region, and the cell drivers, together with different operational and maintenance procedures, have been implemented in the refurbished units resulting in greatly enhanced cell performance and reliability. All 74 cells have now been refurbished and tested for acceptance. This paper gives the results of those tests and the performance of the 26 refurbished cells in the scaled accelerator.
String theory origins of supersymmetry

Abstract The string theory introduced in early 1971 by Ramond, Neveu, and myself has two-dimensional world-sheet supersymmetry. This theory, developed at about the same time that Golfand and Likhtman constructed the four-dimensional super-Poincare algebra, motivated Wess and Zumino to construct supersymmetric field theories in four dimensions. Gliozzi, Scherk, and Olive conjectured the spacetime supersymmetry of the string theory in 1976, a fact that was proved five years later by Green and myself.
Discrete Buffer and Wire Sizing for Link-Based Non-Tree Clock Networks

Clock network is a vulnerable victim of variations as well as a main power consumer in many integrated circuits. Recently, link-based non-tree clock network attracts people's attention due to its appealing tradeoff between variation tolerance and power overhead. In this work, we investigate how to optimize such clock networks through buffer and wire sizing. A two-stage hybrid optimization approach is proposed. It considers the realistic constraint of discrete buffer/wire sizes and is based on accurate delay models. In order to provide reliable and efficient guidance for the optimization, we suggest to apply support vector machine (SVM)-based machine learning as a surrogate for expensive circuit-level simulation. Experimental results on benchmark circuits show that our sizing method can reduce clock skew by 45% on average with very small increase on power dissipation.
A Conceptual Modeling Study on Biosphere–Atmosphere Interactions and Its Implications for Physically Based Climate Modeling

This paper presents a conceptual modeling study on the behaviors of terrestrial biosphere‐atmosphere systems as they relate to multiple equilibrium states and climate variability, and emphasizes their implications for physically based climate modeling. The conceptual biosphere‐atmosphere model consists of equilibrium responses of vegetation and precipitation to each other, dynamics of the vegetation system, and stochastic forcing of precipitation representing the impact of atmospheric internal variability. Using precipitation as the atmospheric variable in describing the biosphere‐atmosphere interactions, this model pertains to regions where vegetation growth is limited by water. Low moisture convergence in the atmosphere combined with high sensitivity of the atmospheric climate to vegetation changes provides the most favorable condition for the existence of multiple equilibrium states. In a coupled biosphere‐atmosphere system with multiple equilibria, experiments varying the stochastic forcing indicate that atmospheric internal variability is an important factor in the long-term variability of the model climate and in its sensitivity to initial conditions. Specifically, the enhancement of low-frequency rainfall variability by vegetation dynamics is most pronounced with a moderate magnitude of atmospheric internal variability and is less pronounced if internal variability is either too large or too small; detecting the existence of multiple equilibria by examining the sensitivity of the coupled model climate to initial conditions is not always reliable since too large an internal variability reduces or even eliminates the model sensitivity to initial conditions. Findings from the conceptual model are confirmed using results from a physically based, synchronously coupled biosphere‐atmosphere model. This study provides guidance for interpreting and understanding the model dependence of biosphere‐atmosphere interaction studies using complex climate system models.
Ni(II)-Bis[(R,R)-N,N'-dibenzylcyclohexane-1,2-diamine]Br2 catalyzed enantioselective Michael additions of 1,3-dicarbonyl compounds to conjugated nitroalkenes.

A highly enantioselective Michael addition of 1,3-dicarbonyl compounds to nitroalkenes has been developed that employs a newly developed Ni(II)−(bis)diamine based catalyst. The reaction scope includes substituted and unsubstituted malonates, β-ketoesters, and nitroalkenes bearing aromatic and aliphatic residues. Ease of synthesis of this complex is noteworthy.