cssi/SciSciGPT-SciSciNet huggingface dataset:
AN INFRARED THROUGH RADIO STUDY OF THE PROPERTIES AND EVOLUTION OF IRDC CLUMPS

We examine the physical properties and evolutionary stages of a sample of 17 clumps within 8 Infrared Dark Clouds (IRDCs) by combining existing infrared, millimeter, and radio data with new Bolocam Galactic Plane Survey (BGPS) 1.1 mm data, Very Large Array radio continuum data, and Heinrich Hertz Telescope dense gas (HCO{sup +} and N{sub 2}H{sup +}) spectroscopic data. We combine literature studies of star formation tracers and dust temperatures within IRDCs with our search for ultracompact (UC) H II regions to discuss a possible evolutionary sequence for IRDC clumps. In addition, we perform an analysis of mass tracers in IRDCs and find that 8 {mu}m extinction masses and 1.1 mm BGPS masses are complementary mass tracers in IRDCs except for the most active clumps (notably those containing UC H II regions), for which both mass tracers suffer biases. We find that the measured virial masses in IRDC clumps are uniformly higher than the measured dust continuum masses on the scale of {approx}1 pc. We use {sup 13}CO, HCO{sup +}, and N{sub 2}H{sup +} to study the molecular gas properties of IRDCs and do not see any evidence of chemical differentiation between hot and cold clumps on the scale of {approx}1more » pc. However, both HCO{sup +} and N{sub 2}H{sup +} are brighter in active clumps, due to an increase in temperature and/or density. We report the identification of four UC H II regions embedded within IRDC clumps and find that UC H II regions are associated with bright ({approx}>1 Jy) 24 {mu}m point sources, and that the brightest UC H II regions are associated with 'diffuse red clumps' (an extended enhancement at 8 {mu}m). The broad stages of the discussed evolutionary sequence (from a quiescent clump to an embedded H II region) are supported by literature dust temperature estimates; however, no sequential nature can be inferred between the individual star formation tracers.« less
Review of Alpha–Decay Data from Doubly–Even Nuclei

Abstract α-decay from doubly-even nuclei throughout the periodic table are reviewed and evaluated. From these data nuclear radius parameters are calculated by using the Preston Formula for α-decay probabilities. The radius parameters for each element behave rather regularly as a function of neutron number. They show minima at the major closed shells and decrease smoothly toward the next shell closure. The same trend is observed for ;ga reduced widths calculated using the Rasmussen formalism. any irregularity or large departure from this behavior indicates probable incorrect input data. This systematic behavior can also be utilized to estimate partial half-lives.
Computer performance variability

During a period when computing on a network is free, users can be very informal about choosing the computer for running their jobs. Certain issues usually dominate this informal evaluation---the convenience of entering jobs, the availability of attractive services, the reliability of the system, and the individual user's familiarity with the system's conventions. These informal evaluations are usually qualitative, but one additional, quantitative characteristic is often included---response time.
Voice output from IBM system/360

The IBM 7770 and 7772 and elements of the New York Stock Exchange Market Data System form a family of IBM devices providing voice output facilities. The devices function similarly in that each gives a computer-generated voice response to a dialed inquiry. The audio generation principle incorporated in the 7770 is a derivative of the original Voice Answer Back principle---that of adjusting word length to fit machine time-slots. Then by access to these words from many input lines, sentences are formed into a voice response. The 7772, on the other hand, generates audio on the "vocoder" principle---that of energizing tone filters and combining the output result first to form words and then sentences in a manner similar to that of the 7770.
Lessons learned from the NEPTUNE power system, and other deep-sea adventures

Abstract The development of underwater science systems presents some challenging technical issues. It seems that the best efforts of the engineers and scientists involved are sometimes inadequate, and projects that once seemed straightforward end up being late or over-budget, or cancelled. This paper will review some of the lessons that may be learned from the examples of three science projects in the deep ocean: the Deep Underwater Muon and Neutrino Detector neutrino detector, the H 2 O observatory, and the power system part of the NEPTUNE regional cabled observatory.
A multiprocessor algorithm for the symmetric tridiagonal eigenvalue problem

A multiprocessor algorithm for finding few or all eigenvalues and the corresponding eigenvectors of a symmetric tridiagonal matrix is presented. It is a pipelined variation of EISPACK routines - BISECT and TINVIT which consists of the three steps: isolation, extraction-inverse iteration, and partial orthogonalization. Multisections are performed for isolating the eigenvalues in a given interval, while bisection or the Zeroin method is used to extract these isolated eigenvalues. After the corresponding eigenvectors have been computed by inverse iteration, the modified Gram-Schmidt method is used to orthogonalize certain groups of these vectors. Experiments on the Alliant FX/8 and CRAY X-MP/48 multiprocessors show that this algorithm achieves high speed-up over BISECT and TINVIT; in fact it is much faster than TQL2 when all the eigenvalues and eigenvectors are required.
Almost integral TQFTs from simple Lie algebras

Almost integral TQFTs were introduced by Gilmer (G). The aim of this paper is to modify the TQFT of the category of extended 3- cobordisms given by (T) to obtain almost integral TQFT. AMS Classification 57M27, 57R56 Inspired by a 3-dimensional interpretation of the Jones polynomial for knots, Witten predicted that one can define topological invariants for 3-manifolds us- ing simple complex Lie algebras. The first concrete construction was obtained by Reshetikhin and Turaev (RT) for sl2. Soon after, similar invariants were constructed for all simple Lie algebras. They are called the Witten-Reshetikhin- Turaev invariants (WTR-invariants for short) or quantum invariants because Reshetikhin and Turaev's construction is based on the theory of quantum groups. It was also Witten's vision that the WTR-invariants can be extended to the Topological Quantum Field Theory (TQFT) in a rather natural manner. Loosely speaking, a TQFT with base ring K is a functor from the category C to the category of K-modules where the objects in C are surfaces and morphisms in C are 3-dimensional cobordisms. We denote a TQFT by a pair (T , τ) where T and τ are maps between objects and morphisms respectively. Most known TQFTs have anomalies. Anomalies can be resolved by introducing p1-structure as in (BHMV) or by studying the category of extended 3-cobordisms as in (T). In this paper we follow the latter. One of the features of extended 3-cobordisms is that they contain embedded colored ribbon graphs. (See Section 2.2 for more details about TQFT and ribbon graph.) For each simple complex Lie algebra g and certain integer r, one can define a TQFT (T g r , τ g r). In this case, the col- ors of the ribbon graphs come from the representations of the quantum group Uv(g) associated to g with the parameter v equal to a primitive r-th root of unity.
Chandra Observation of the X-Ray Source Population of NGC 6946

We present the results of a study of discrete X-ray sources in NGC 6946 using a deep Chandra ACIS observation. Based on the slope of the log N-log S distribution and the general correlation of sources with the spiral arms, we infer that the overall discrete source sample in NGC 6946 is dominated by high mass X-ray binaries, in contrast to the source distributions in M31 and the Milky Way. This is consistent with the higher star formation rate in NGC 6946 than in those galaxies. We find that the strong X-ray sources in the region of the galactic center do not correlate in detail with images of the region in the near-IR, although one of them may be coincident with the galactic center. The non-central ultra-luminous X-ray source in NGC 6946, previously identified with a supernova remnant, has an X-ray spectrum and luminosity that is inconsistent with either a traditional pulsar wind nebula or a blast wave remnant.
Metal-Complex-Decorated Homochiral Heterobimetallic Telluride Single-Stranded Helix

Solvothermal reaction of a mixture of Sn, Mn, and Te at 200 °C using teta as the solvent yields a novel inorganic−organic hybrid solid [Mn(teta)(en)]·[Mn(teta)][Mn(SnTe4)2·Mn(teta)] (teta = triethylenetetramine and en = ethylenediamine; 1), which has a homochiral single-stranded helical structure. The material is a semiconductor with a band gap of 0.88 eV and shows paramagnetic behavior between 2 and 300 K.
Audit committee, board of director characteristics, and earnings management

Abstract This study examines whether audit committee and board characteristics are related to earnings management by the firm. A negative relation is found between audit committee independence and abnormal accruals. A negative relation is also found between board independence and abnormal accruals. Reductions in board or audit committee independence are accompanied by large increases in abnormal accruals. The most pronounced effects occur when either the board or the audit committee is comprised of a minority of outside directors. These results suggest that boards structured to be more independent of the CEO are more effective in monitoring the corporate financial accounting process.
Quasiparticle band structure of HgSe

Motivated by a recent discussion about the existence of a fundamental gap in HgSe [Phys. Rev. Lett. {bold 78}, 3165 (1997)], we calculate the quasiparticle band structure of HgSe within the GW approximation for the electron self-energy. The band-structure results show that HgSe is a semimetal, which is in agreement with most experimental data. We observe a strong wave-vector dependence of the self-energy of the lowest conduction band, leading to an increased dispersion and a small effective mass. This may help to interpret recent photoemission spectroscopy measurements. {copyright} {ital 1998} {ital The American Physical Society}
Publications of the state academies of science

Since their origin, state academies of science have promoted and disseminated regional scientific research through the publication of journals and conference proceedings. For the most part, these multidisciplinary publications have been overshadowed by the more voluminous, specialized publications of the larger scientific societies and publishers. Nevertheless, an examination of the titles currently published by the state academies of science indicates that on the basis of content, subscription levels, library ownership rates, indexing/abstracting practices and professional citation levels, it can be concluded that the publications of the state academies of science remain an important means for the distribution of scientific research. Appendices provide a list of publications and a list of web sites.
Improved Navigation by Combining VOR/DME Information and Air Data

Navigational accuracy improvement by combining VOR/DME information with airspeed and heading data via maximum likelihood filter, using small airborne computer
Systematics of moduli stabilization, inflationary dynamics and power spectrum

We study the scalar sector of type IIB superstring theory compactified on Calabi-Yau orientifolds as a place to find a mechanism of inflation in the early universe. In the large volume limit, one can stabilize the moduli in stages using perturbative method. We relate the systematics of moduli stabilization with methods to reduce the number of possible inflatons, which in turn lead to a simpler inflation analysis. Calculating the order-of-magnitude of terms in the equation of motion, we show that the methods are in fact valid. We then give the examples where these methods are used in the literature. We also show that there are effects of non-inflaton scalar fields on the scalar power spectrum. For one of the two methods, these effects can be observed with the current precision in experiments, while for the other method, the effects might never be observable.
Total synthesis of (±)-welwitindolinone A isonitrile

A highly stereoselective total synthesis of the alkaloid natural product welwitindolinone A isonitrile has been completed. The synthesis utilizes a chloronium ion mediated semi-pinacol rearrangement to simultaneously install the C10 quaternary center and neopentyl chlorine and a novel anionic cyclization to construct the spiro-oxindole with complete stereocontrol.
Query by example

In the last few years we have witnessed a trend to appeal to the non-professional user who has little or virtually no computer or mathematical background.
SUM RULES AND MOMENTS OF THE NUCLEON SPIN STRUCTURE FUNCTIONS

The nucleon has been used as a laboratory to investigate its own spin structure and quantum chromodynamics. New experimental data on nucleon spin structure at low to intermediate momentum transfers combined with existing high momentum transfer data offer a comprehensive picture of the transition region from the confinement regime of the theory to its asymptotic freedom regime. Insight for some aspects of the theory is gained by exploring lower moments of spin structure functions and their corresponding sum rules (i.e. the Gerasimov–Drell–Hearn, Bjorken and Burkhardt–Cottingham). These moments are expressed in terms of an operator-product expansion using quark and gluon degrees of freedom at moderately large momentum transfers. The sum rules are verified to good accuracy assuming that no singular behavior of the structure functions is present at very high excitation energies. The higher-twist contributions have been examined through the moments evolution as the momentum transfer varies from higher to lower values. Furthermore, QCD-inspired low-energy effective theories, which explicitly include chiral symmetry breaking, are tested at low momentum transfers. The validity of these theories is further examined as the momentum transfer increases to moderate values. It is found that chiral perturbation calculations agree reasonably well with the first moment of the spin structure function g1 at momentum transfer of 0.1 GeV2 but fail to reproduce the neutron data in the case of the generalized polarizability δLT.
A capstone design project to meet the needs of the changing power systems industry and satisfy new accreditation standards

Currently, two motivators are effecting change in power systems education. First, the industry's transition to a more competitive environment is requiring changes in the content and pedagogy of power systems education. Second, engineering education as a whole is seeking to modify its curriculum to reflect a better balance between science and education in order to better meet the needs of industry. These curricular changes are largely a result of revised Accreditation Board for Engineering and Technology (ABET) accreditation requirements. In response to these changes, new curriculum and analysis tools were developed for a power systems capstone design course. The project integrates market economics and socio-political considerations with transient stability analysis and transmission planning. A power systems analysis package and an economic analysis tool were developed for use with this project. Student evaluations of the course in which the project was implemented indicate that the curriculum successfully addresses a broad range of ABET accreditation criteria.
The photochemistry of acetylenic ethers. A novel carbon-oxygen to carbon-carbon bond conversion

Abstract Irradiation of acetylenic ethers in methanol gives homologated esters via a formal [1,3]-oxygen-to-carbon migration involving a ketene intermediate.
Solid-state NMR studies of the structure and mechanisms of proteins

Magic-angle spinning solid-state NMR experiments are well suited to investigating the structures and mechanisms of important proteins that are inaccessible to X-ray crystallography and solution NMR spectroscopy, including membrane proteins and disease-related protein aggregates. Good progress has been made in the development of methods for the complete structure determination of small (<20 kDa) solid proteins using uniformly 13C, 15N-labeled samples. Studies of selectively labeled proteins focusing on labeled active sites have yielded insights into the mechanisms of enzymes and of membrane proteins involved in energy and signal transduction. Studies of selectively labeled synthetic peptides have yielded structural models for biomedically important systems, including amyloid fibrils and surface-associated peptides involved in biomineralization and cell adhesion. Novel NMR and biochemical methods are being developed to target solid-state NMR experiments within large proteins and whole cells. These approaches are being used to investigate mechanisms of transmembrane signaling by membrane receptors and to characterize binding interactions between antibiotics and bacterial cell walls. Thus, solid-state NMR is proving to be a valuable biophysical tool for probing structure and dynamics in a wide range of biomolecules.
INFLATING HOT JUPITERS WITH OHMIC DISSIPATION

We present a new, magnetohydrodynamic mechanism for inflation of close-in giant extrasolar planets. The idea behind the mechanism is that current, which is induced through interaction of atmospheric winds and the planetary magnetic field, results in significant Ohmic dissipation of energy in the interior. We develop an analytical model for computation of interior Ohmic dissipation, with a simplified treatment of the atmosphere. We apply our model to HD209458b, Tres-4b, and HD189733b. With conservative assumptions for wind speed and field strength, our model predicts a generated power that appears to be large enough to maintain the transit radii, opening an unexplored avenue toward solving a decade-old puzzle of extrasolar gas giant radius anomalies.
The role of self selection, usage uncertainty and learning in the demand for local telephone service

Telephone services are often characterized by the presence of ‘fixed’ plans, involving only a fixed monthly fee, as well as ‘measured’ plans, with both fixed fees and per-unit charges for usage. Consumers are faced with the decisions of which plan to choose and how much to use the phone and these decisions are not, in general, independent. Due to the presence of a time lag between plan choice and usage decisions, consumers are uncertain about usage at the plan-choice stage. We develop a structural discrete/continuous model of plan choice and usage decisions of consumers that accounts for such uncertainty. Prior research has also found that consumers switch less often from fixed plans to measured plans to gain from potential savings than vice versa. Consumer uncertainty regarding their mean usage levels and different rates of learning by consumers in the two plans is a potential explanation for this phenomenon. We extend our discrete/continuous model to account for consumer learning about their mean usage and estimate different rates of learning for the two types of plans. We estimate our model using data from the 1986 Kentucky local telephone tariff experiment. Even in the absence of any price variation over time, we are able to measure the price elasticities both of usage and of choice of plan. Using our parameter estimates, we simulate the effects of the introduction of a metered plan in a market with only a fixed plan and vice versa, on both firm revenues and consumer surplus. We also find that consumers learn very rapidly if they are on the measured plan but learn very slowly when they are on the fixed plan. We investigate an alternative assumption on the nature of the learning process in which only consumers in the measured plan have an opportunity to learn. We find that our empirical results are robust to this change of specification. We conduct counterfactual simulations to simulate enhanced calling plans from the firm and consumer points of view. Additional simulations to measure the value of information in this category are also carried out. We compute the value of both complete information, where the entire uncertainty about future usage is resolved, as well as that of limited information, where the consumer's uncertainty about mean usage is resolved, but the uncertainty about specific month-to-month usage remains. We find that the value of information is modest. We also find that a large proportion of the value of information is that about the mean usage, with the value of the information about a specific month's usage being relatively small.
Probing the desert with ultra-energetic neutrinos from the sun and the earth

Abstract Realistic superstring models generically give rise to exotic matter states, which arise due to the “Wilson-line” breaking of the non-Abelian unifying gauge symmetry. Often such states are protected by a gauge or local discrete symmetry and therefore may be stable or meta-stable. We study the possibility of a flux of high energy neutrinos coming from the sun and the earth due to the annihilation of such exotic string states. We also discuss the expected flux for other heavy stable particles – like the gluino LSP. We comment that the detection of ultra-energetic neutrinos from the sun and the earth imposes model independent constraints on the high energy cutoff, as for example in the recently entertained TeV scale Kaluza–Klein theories. We therefore propose that improved experimental resolution of the energy of the muons in neutrino detectors together with their correlation with neutrinos from the sun and the center of the earth will serve as a probe of the desert in Gravity Unified Theories.
Point queue models: A unified approach

Abstract In transportation and other types of facilities, various queues arise when the demands of service are higher than the supplies, and many point and fluid queue models have been proposed to study such queueing systems. However, there has been no unified approach to deriving such models, analyzing their relationships and properties, and extending them for networks. In this paper, we derive point queue models as limits of two link-based queueing model: the link transmission model and a link queue model. With two definitions for demand and supply of a point queue, we present four point queue models, four approximate models, and their discrete versions. We discuss the properties of these models, including equivalence, well-definedness, smoothness, and queue spillback, both analytically and with numerical examples. We then analytically solve Vickrey’s point queue model and stationary states in various models. We demonstrate that all existing point and fluid queue models in the literature are special cases of those derived from the link-based queueing models. Such a unified approach leads to systematic methods for studying the queueing process at a point facility and will also be helpful for studies on stochastic queues as well as networks of queues.
Stereoselective SN2' additions of organocuprates to homochiral acyclic vinyloxiranes

Abstract Additions of various methylcopper reagents to the homochiral acyclic vinyloxiranes A14, A15, B6–B9, and C5, C6 were performed in order to evaluate E/Z and syn/anti preferences. The unsubstituted oxiranes A14 and A15 gave a mixture of SN2 and SN2' substitution products with the four reagents examined, LiMe2Cu, LiMeCuCN, BrMgMe2Cu, and LiMeCuI · BF3. The more highly substituted systems B6–B9 derived from geraniol and C5, C6 derived from nerol yielded only SN2' products. The (Z)-allylic alcohol derivatives B8 and C6 and LiMeCuCN gave the best anti/syn ratios (99:1 and 97:3, respectively). In both cases the newly formed double bond was exclusively E.
Polarization Sweeps in Rotation-powered Pulsars

We reexamine the characteristic polarization angle sweep of rotation-powered pulsars and calculate the expected deviations from this sweep caused by aberrational effects and by polar-cap current flow. We find that in addition to the previously known phase shift of the entire sweep by ΔΦ = -4r/RL (when RL is the light cylinder distance), aberration shifts the polarization angle itself by ΔΨ = -(10/3)(r/RL) cos α. Similarly, current flow above the polar cap shifts the polarization sweep by ΔΨ = (10/3)(r/RL)(J/JGL) cos α, potentially providing a method of directly measuring the magnitude of the current. The competition between these two effects produces a potentially observable signature in the polarization angle sweep. Although these effects may appear similar to orthogonal mode shifts, they are an independent phenomenon with distinct observational characteristics.
The Influence of Affect on Beliefs, Preferences and Financial Decisions

Neuroeconomics research shows that brain areas that generate emotional states also process information about risk, rewards, and punishments, suggesting that emotions influence financial decisions in a predictable and parsimonious way. We find that positive emotional states such as excitement induce people to take risks and to be confident in their ability to evaluate investment options, while negative emotions such as anxiety have the opposite effects. Beliefs are updated so as to maintain a positive emotional state by ignoring information that contradicts individuals’ prior choices. Marketplace features or outcomes of past choices may change emotions and thus influence future financial decisions.
Tether-Cutting Energetics of a Solar Quiet Region Prominence Eruption

We study the morphology and energetics of a slowly evolving quiet-region solar prominence eruption occurring on 1999 February 8-9 in the solar north polar crown region, using soft X-ray data from the soft X-ray telescope (SXT) on Yohkoh and Fexv EUV 284 Angstrom data from the EUV Imaging Telescope (EIT) on the Solar and Heliospheric Observatory (SOHO). After rising at approximately equal to l kilometer per second for about six hours, the prominence accelerates to a velocity of approximately equal to 10 kilometers per second, leaving behind EUV and soft X-ray loop arcades of a weak flare in its source region. Intensity dimmings occur in the eruption region cospatially in EUV and soft X-rays, indicating that the dimmings result from a depletion of material. Over the first two hours of the prominences rapid rise, flare-like brightenings occur beneath the rising prominence that might correspond to tether-cutting magnetic reconnection. These brightenings have heating requirements of up to approximately 10(exp 28)-10(exp 29) ergs, and this is comparable to the mechanical energy required for the rising prominence over the same time period. If the ratio of mechanical energy to heating energy remains constant through the early phase of the eruption, then we infer that coronal signatures for the tether cutting may not be apparent at or shortly after the start of the fast phase in this or similar low-energy eruptions, since the plasma-heating energy levels would not exceed that of the background corona.
Intergalactic Photon Spectra from the Far-IR to the UV Lyman Limit for 0 < z < 6 and the Optical Depth of the Universe to High-Energy Gamma Rays

Table 1 in our paper had erroneous numbers for the coefficients fitting the parametric form for the optical depth of the universe to gamma-rays; tau. The correct values for these parameters as described in the original text are given in the table for various redshifts for the baseline model (upper row) and fast evolution (lower row) for each individual redshift.
Non-trivial fixed points of the renormalization group in six dimensions

Abstract We start a systematic analysis of supersymmetric field theories in six dimensions. We find necessary conditions for the existence of non-trivial interacting fixed points. String theory provides us with examples of such theories. We conjecture that there are many other examples.
Many-body interactions among adsorbed atoms and molecules within carbon nanotubes and in free space

Abstract This Letter evaluates three-body triple dipole (DDD) interactions for quasi-one-dimensional phases of He, Ne, H 2 , Ar, Kr and Xe confined within a bundle of nanotubes. We find a significant reduction in the pair potential well depth due to the DDD effect. We carry out ab initio calculations on linear and equilateral configurations of the H 2 trimer and find that overlap interactions do not greatly change the DDD interaction in the linear configuration when the spacing is greater than about 3 A . However, the DDD interaction alone is clearly insufficient for the triangular configurations studied.
Luminous Compact Blue Galaxies in Intermediate-Redshift Galaxy Clusters: A Significant but Extreme Butcher-Oemler Population

We identify a population of luminous compact blue galaxies (LCBGs) in two galaxy clusters: MS 0451.6-0305 (z = 0.54) and Cl 1604+4304 (z = 0.9). LCBGs are identified via photometric characteristics and photometric redshifts derived from broad- and narrowband images taken with the WIYN telescope and the Hubble Space Telescope (HST). We analyze their surface densities and clustering properties to find that they compose a statistically significant portion (42% and 53%, respectively) of the Butcher-Oemler (BO) galaxies in both clusters and that their spatial distributions are best characterized by a shell model. The enhancement of the projected space density of LCBGs with MB < -18.5 in the clusters relative to the field is 3-10 times higher than the BO population as a whole but 2 times lower than the red population, except in the core where LCBGs are absent. Assuming some fading, a natural descendant would be small, low-luminosity galaxies found preferentially in today's clusters, such as dE galaxies.
Domestic Hot Water Heating Using Hot Air Solar Collectors

The efficiency of a finned coil type heat exchanger mounted in the solar collector air outlet duct of a space heating system for providing hot water in the spring, fall and summer months was determined with a series of equations and graphically represented. The equations were used to determine the effect of coil fin surface area on the hybrid system efficiency. From an equation calculating the air to water heat transfer rate, the heat balance for the air to water heat exchangers can be determined. Other thermal performance parameters were calculated prior to the development of a graphical solution to the evaluation. The graph can be applied to economic tradeoff studies for determining the optimum heat exchanger area relative to that of the collector. An experimental solar air heater test facility indicated the limitations of an air to water hybrid solar heating system.
Renegotiation‐Proof Tariff Agreements

The institutional features of the World Trade Organization motivate the use of renegotiation-proofness as an equilibrium concept in repeated tariff-setting games. This paper shows the existence of a renegotiation-proof equilibrium that reduces tariffs below the noncooperative level. It is found that the one-shot Nash equilibrium cannot be used as a punishment to support such treaties. Punishments are either Pareto-efficient or one country barely accepts them. If the punishing country is hurt by the punishment then punishments will be as short as possible. If the agreement tariff levels are not Pareto-efficient then one country barely goes along with the agreement.
Simple Synthesis of Amides and Weinreb Amides Using PPh3 or Polymer‐Supported PPh3 and Iodine

The combination of PPh3/I2 has been shown to be effective for conversion of a range of carboxylic acids to 2°, 3°, and Weinreb amides. Simplification of the procedure was possible with the use of polymer-supported PPh3/I2. Weinreb amides produced via the use of polymer-supported PPh3 could be filtered through a short silica gel plug and used in further transformations. Thus, use of polymer-supported PPh3 offers potential applicability to diversity-oriented reactions. Formal total syntheses of apocynin and pratosine, as well as syntheses of anhydrolychorinone and hippadine, have been achieved via the use of this amide-forming method. An attempt has been made to gain insight into this reaction.
The Effect of Control Systems on Trust and Cooperation in Collaborative Environments

Because of conflicting incentives among participants, collaborations (e.g., strategic alliances, joint ventures, and work teams) present a significant control challenge to managerial accountants. On the one hand, formal controls such as sanctioning and monitoring systems improve cooperation by reducing the incentives for opportunistic behavior. On the other hand, prior research finds that the mere presence of a control system causes decision makers to view the collaborative setting as noncooperative, and other collaborators as untrustworthy. In this paper, we conduct two experiments in which participants act as business collaborators. Through these experiments, we examine the effects of control on trust and cooperation in collaborative settings. Specifically, we posit and provide evidence that a strong control system can enhance the level of trust among collaborators. The mediating role of control‐induced cooperation provides the mechanism by which control systems can increase trust in collaborative envir...
The guidebook, the friend, and the room: visitor experience in a historic house

In this paper, we describe an electronic guidebook prototype and report on a study of its use in a historic house. Supported by mechanisms in the guidebook, visitors constructed experiences that had a high degree of interaction with three entities: the guidebook, their companions, and the house and its contents. For example, we found that most visitors played audio descriptions through speakers (rather than using headphones or reading textual descriptions) to facilitate communication with their companions.
A mathematical theory of citing

Recently we proposed a model in which when a scientist writes a manuscript, he picks up several random papers, cites them, and also copies a fraction of their references. The model was stimulated by our finding that a majority of scientific citations are copied from the lists of references used in other papers. It accounted quantitatively for several properties of empirically observed distribution of citations; however, important features such as power-law distributions of citations to papers published during the same year and the fact that the average rate of citing decreases with aging of a paper were not accounted for by that model. Here, we propose a modified model: When a scientist writes a manuscript, he picks up several random recent papers, cites them, and also copies some of their references. The difference with the original model is the word recent. We solve the model using methods of the theory of branching processes, and find that it can explain the aforementioned features of citation distribution, which our original model could not account for. The model also can explain “sleeping beauties in science;” that is, papers that are little cited for a decade or so and later “awaken” and get many citations. Although much can be understood from purely random models, we find that to obtain a good quantitative agreement with empirical citation data, one must introduce Darwinian fitness parameter for the papers. © 2007 Wiley Periodicals, Inc.
Using neural-net computing to formulate real-time control strategies

Abstract In this paper, we propose a new neural-net approach to learning appropriate control actions. It is not based on the more commonly accepted approach of learning a system emulator and a control-action generator with supervised learning implemented through minimization of errors. Instead, the net observes and records, and adjusts local activation and attention to reflect the frequency of occurrences. Such a net can track the time variational characteristics of physical plants and is compatible with the learning of real-time fuzzy controls.
Van der Waals Forces in Helium

A variational method of calculating perturbation energy has been applied to the first two terms of a rapidly converging series expansion of the mutual potential energy of two helium atoms. The result is compared with the much simpler second-order perturbation scheme of Margenau, which it tends to support. The same variational method was then used with the perturbing potential in closed form. This involves the calculation of integrals not previously evaluated. The result validates the previous expansion of the potential. We obtain, for the van der Waals interaction of two unexcited helium atoms: $\ensuremath{\epsilon}=\ensuremath{-}(\frac{A}{{R}^{6}}){1+\frac{6.26}{{R}^{2}}+\frac{51.2}{{R}^{4}}+\ensuremath{\cdots}} \mathrm{ergs},$ where $R$ is the atomic separation with the first Bohr radius (0.5282 angstrom) as unit distance. The complexity of the integrations requires the use of simple exponential wave functions of the Hartree type; the resulting value of the coefficient $A$ is therefore poor, but this coefficient is well known from other work. It yields a polarization molecule with a dissociation energy of 0.30\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}16}$ erg. The bracketed expression giving the relative contributions of the higher order terms is the chief contribution of the present method of attack.
Three New Cool Brown Dwarfs Discovered with the Wide-field Infrared Survey Explorer (WISE) and an Improved Spectrum of the Y0 Dwarf WISE J041022.71+150248.4

As part of a larger search of Wide-field Infrared Survey Explorer (WISE) data for cool brown dwarfs with effective temperatures less than 1000 K, we present the discovery of three new cool brown dwarfs with spectral types later than T7. Using low-resolution, near-infrared spectra obtained with the NASA Infrared Telescope Facility and the Hubble Space Telescope, we derive spectral types of T9.5 for WISE J094305.98+360723.5, T8 for WISE J200050.19+362950.1, and Y0: for WISE J220905.73+271143.9. The identification of WISE J220905.73+271143.9 as a Y dwarf brings the total number of spectroscopically confirmed Y dwarfs to 17. In addition, we present an improved spectrum (i.e., higher signal-to-noise ratio) of the Y0 dwarf WISE J041022.71+150248.4 that confirms the Cushing et al. classification of Y0. Spectrophotometric distance estimates place all three new brown dwarfs at distances less than 12 pc, with WISE J200050.19+362950.1 lying at a distance of only 3.9-8.0 pc. Finally, we note that brown dwarfs like WISE J200050.19+362950.1 that lie in or near the Galactic plane offer an exciting opportunity to directly measure the mass of a brown dwarf via astrometric microlensing.
Tracking control of mechanical systems in the presence of nonlinear dynamic friction effects

In this paper, we design an observer-based exact model knowledge position tracking controller for a second-order mechanical system with nonlinear load dynamics and a nonlinear dynamic friction model. Since the controller requires an estimate of the unmeasurable friction state, we demonstrate how the friction dynamics can be exploited to design three different observers which foster different transient response characteristics for the composite closed-loop system. We then present two adaptive controllers which utilize nonlinear observer/filter structures to provide for asymptotic position tracking while compensating for selected parametric uncertainty. Dynamic simulation and experimental results are utilized to illustrate control performance.
Left atrial inflow propagation rate derived by transesophageal color M-mode echocardiography is a promising index of preload.

Background: Pulmonary capillary wedge pressure (PCWP) is a useful index of preload and an important determinant of cardiac function. Hypothesis: We postulated that the rate of blood propagating into the left atrium (LAIF-PR) would be a useful measure of PCWP in critically ill patients. Methods: Fifty-two critically ill patients (36 men/16 women) receiving mechanical ventilation were studied by multiplane transesophageal echocardiography (TEE). Left atrial inflow propagation rate was measured in systole and diastole as the slope of the color M-mode signal entering the left atrium from the right upper pulmonic vein. Results: Systolic and diastolic LAIF-PRs were feasible in 49 and 44 patients, respectively. Mean (± 1 standard deviation) LAIF-PR in systole was 40 ± 26 cm/s (range 11-132) and in diastole 34 ± 22 cm/s (range 5-102). Negative correlations with PCWP (mean 19 ± 9 mmHg; range 3-40) were good for LAIF-PR in systole (r = −0.71, standard error of estimate [SEE] = 6 mmHg; p< 0.0001) and diastole (r = −0.71, SEE = 6 mmHg; p < 0.0001). Mean ejection fraction was 52 ± 22% (range 15-88) and cardiac output was 6.97 ±3.52 l/min (range 2.26-17.93). Multivariate regression showed PCWP as the only independent predictor of systolic (p < 0.0001) and diastolic (p < 0.0001) LAIF-PR among age, heart rate, cardiac output, ejection fraction, or left atrial diameter. Conclusions: Left atrial inflow propagation rate derived by color M-mode TEE aligned with the right upper pulmonic vein is a promising new index of preload. Future studies addressing the determinants of LAIF-PR, such as left atrial compliance, are needed.
An Instrument for Investigation of the Cosmic Microwave Background Radiation at Intermediate Angular Scales

We describe an off-axis microwave telescope for observations of the anisotropy in the cosmic microwave background (CMB) radiation on angular scales between 05 and 3°. The receiver utilizes cryogenic high electron mobility transistor (HEMT) amplifiers and detects the total power in multiple 3 GHz wide channels. Both frequency and polarization information are recorded allowing discrimination between CMB radiation and potential foreground sources and allowing checks for systematic effects. The instrumental radiometric offset is small (~1 mK). Data are taken by rapidly sampling while sweeping the beam many beamwidths across the sky. After detection, a spatio-temporal filter is formed in software that optimizes the sensitivity in a multipole band in the presence of atmospheric fluctuations. Observations were made from Saskatoon, Saskatchewan (SK), Canada, during the winter of 1993 with six channels between 27.6 and 34.0 GHz, in 1994 with 12 channels between 27.6 and 44.1 GHz, and in 1995 with six channels between 38.2 and 44.1 GHz. The performance of the instrument and assessment of the atmospheric noise at this site are discussed.
A Unified Approach to Combinatorial Formulas for Schubert Polynomials

Schubert polynomials were introduced in the context of the geometry of flag varieties. This paper investigates some of the connections not yet understood between several combinatorial structures for the construction of Schubert polynomials; we also present simplifications in some of the existing approaches to this area. We designate certain line diagrams for permutations known as rc-graphs as the main structure. The other structures in the literature we study include: semistandard Young tableaux, Kohnert diagrams, and balanced labelings of the diagram of a permutation. The main tools in our investigation are certain operations on rc-graphs, which correspond to the coplactic operations on tableaux, and thus define a crystal graph structure on rc-graphs; a new definition of these operations is presented. One application of these operations is a straightforward, purely combinatorial proof of a recent formula (due to Buch, Kresch, Tamvakis, and Yong), which expresses Schubert polynomials in terms of products of Schur polynomials. In spite of the fact that it refers to many objects and results related to them, the paper is mostly self-contained.
Earnings management by acquiring firms in stock for stock mergers

Abstract We investigate whether acquiring firms attempt to increase their stock price prior to a stock for stock merger in order to reduce the cost of buying the target. In a sample of stock for stock mergers completed between 1985 and 1990, we find that acquiring firms manage earnings upward in the periods prior to the merger agreement. Our results also indicate that the degree of income increasing earnings management is positively related to the relative size of the merger.
A program for the nonlinear static and dynamic analysis of arbitrarily loaded shells of revolution

Abstract A digital computer program for the geometrically nonlinear static and dynamic response of arbitrarily loaded shells of revolution is described. The governing partial differential equations are based upon Sanders' nonlinear thin shell theory for the conditions of small strains and moderately small rotations. The governing equations are reduced to uncoupled sets of four linear, second order, partial differential equations in the meridional and time coordinates by expanding the dependent variables in a Fourier sine or cosine series in the circumferential coordinate and treating the nonlinear modal coupling terms as pseudo loads. The derivatives with respect to the meridional coordinate are approximated by central finite differences, and the displacement accelerations are approximated by the implicit Houbolt backward difference scheme with a constant time interval. At every load step or time step each set of difference equations is repeatedly solved, using an elimination method, until all solutions have converged. Results from the program are compared to previously published data for several problems, and the versatility, efficiency, and limitations of the program are candidly evaluated.
A Simple Method to Find All Lensed Quasars

We demonstrate that gravitationally lensed quasars are easily recognized using image subtraction methods as time variable sources that are spatially extended. For Galactic latitudes |b| 20°, lensed quasars dominate the population of spatially extended variable sources, although there is some contamination from variable star pairs, variable star-quasar pairs, and binary quasars that can be easily controlled using other information in the survey such as the object light curves and colors. This method will allow planned large-scale synoptic surveys to find lensed quasars almost down to their detection limits without the need for extensive follow-up observations.
Hyperkähler sigma model and field theory on Gibbons-Hawking spaces

We describe a novel deformation of the 3-dimensional sigma model with hyperkahler target, which arises naturally from the compactification of a 4-dimensional $ \mathcal{N} $ = 2 theory on a hyperkahler circle bundle (Gibbons-Hawking space). We derive the condition for which the deformed sigma model preserves 4 out of the 8 supercharges. We also study the contribution from a NUT center to the sigma model path integral, and find that supersymmetry implies it is a holomorphic section of a certain holomorphic line bundle over the hyperkahler target. We study explicitly the case where the original 4-dimensional theory is pure U(1) super Yang-Mills, and show that the contribution from a NUT center in this case is simply the Jacobi theta function.
A knowledge-theoretic analysis of uniform distributed coordination and failure detectors

It is shown that, in a precise sense, if there is no bound on the number of faulty processes in a system with unreliable but fair communication, Uniform Distributed Coordination (UDC) can be attained if and only if a system has perfect failure detectors. This result is generalized to the case where there is a bound t on the number of faulty processes. It is shown that a certain type of generalized failure detector is necessary and sufficient for achieving UDC in a context with at most t faulty processes. Reasoning about processes' knowledge as to which other processes are faulty plays a key role in the analysis.