cssi/SciSciGPT-SciSciNet huggingface dataset:
Miss distance analysis for command guided missiles

A concise theoretical technique is presented for estimating the minimum miss distance capability of command guided missile systems using synthetic proportional navigation. The effect of the parameter values on the system capability is shown to be a function of range-to-intercept; the technique enables the system designer and analyst to quantify system performance and to develop a systematic understanding of the performance limitations of command guidance systems at each intercept range. New analytical equations based upon adjoint theory are developed for statistical miss distance caused by target maneuver, range-dependent, servo, glint and atmosphere noises for command guided systems. An optimal total system time constant is derived which yields the minimum statistical miss distance. Realistic constraints on the minimum achievable system time constant are considered. The equations derived for the optimal total system time constant are valuable to the system designer for minimizing miss distance over the ranges of system parameters and limitations, and intercept conditions.
Contact control for advanced applications of light weight arms

Many applications of robotic and teleoperated manipulator arms require operation in contact and noncontact regimes. This paper deals with both regimes and the transition between them with special attention given to problems of flexibility in the links and drives. This is referred to as contact control. Inverse dynamics is used to plan the tip motion of the flexible link so that the free motion can stop very near the contact surface without collision due to overshoot. Contact must occur at a very low speed since the high frequency impact forces are too sudden to be affected by any feedback generated torques applied to a joint at the other end of the link. The effects of approach velocity and surface properties are discussed. Force tracking is implemented by commands to the deflection states of the link and the contact force. This enables a natural transition between tip position and tip force control that is not possible when the arm is treated as rigid. The effects of feedback gain, force trajectory, and desired final force level are of particular interest and are studied. Experimental results are presented on a one-link arm and the system performance in the overall contact task is analyzed. Extension to multi-link cases with potential applications are discussed.
Selection and evaluation of high strength steel for hutton TLP tension leg elements

The development of the tension leg platform (TLP) for the Hutton Field in the North Sea represents the first application of this deepwater concept. The use of vertical tension legs as the mooring system is the most novel part of the TLP design. One of the unique features of the tension legs is the use of 92.5-mm (3.64-in.) thick tubulars forged from 3 1/2 percent Ni-Cr-Mo-V high-strength steel (795 MPa (115.3 ksi) minimum yield strength) as mooring elements. Because of the importance of these elements to the survival of the TLP, the chemical composition and the steelmaking procedure were critically examined and optimized. In addition, extensive evaluation of the corrosion fatigue behavior of the steel was undertaken. This paper discusses the basis for the steel selection and specification, the results of the rigorous corrosion fatigue test program, and the assessment of the variation of properties along the length and through the thickness of full-size components. These results illustrate the suitability of the proposed high-strength steel for the mooring system application and establish confidence in both steelmaking and quality control procedures.
Freshwater export from the Labrador Current to the North Atlantic Current at the Tail of the Grand Banks of Newfoundland

Abstract Historical hydrographic data, spanning the period 1896–2006, are used to examine the annual mean and seasonal variations in the distribution of freshwater along and across the shelf/slope boundary along the Labrador and Newfoundland Shelves and the Grand Banks of Newfoundland. Particular attention is paid to the export of freshwater along the eastern Grand Banks, between Flemish Cap and the Tail of the Grand Banks, as this has long been identified as a preferential region for the loss of mass and freshwater from the boundary. The data are combined into isopycnally averaged long-term annual and monthly mean gridded property fields and the evolving distribution of fresh arctic-origin water is analyzed in fields of salinity anomaly, expressed as departures from the “central water” temperature–salinity relation of the Gulf Stream. The climatology confirms that cold/fresh northern-source waters are advected offshore within the retroflecting Labrador Current along the full length of the boundary between Flemish Cap and the Tail of the Grand Banks. In fact, it is estimated that most of the equatorward baroclinic transport at the boundary must retroflect back toward the north in order to explain the annual mean distribution of salinity in the climatology. While the retroflection of the Labrador Current appears seasonally robust, the freshwater distribution within the retroflection region varies in response to (1) the freshness of the water available for export which is set by the arrival and rapid flushing of the seasonal freshwater pulse at the boundary, (2) seasonal buoyancy forcing at the surface which alters the vertical stratification across the retroflection region, restricting certain isopycnal export pathways, and (3) the density structure along the eastern Grand Banks, which defines the progressive retroflection of the Labrador Current.
Cathodoluminescence studies of the 1.4 eV bands in CdTe

Cathodoluminescence at 80/sup 0/K was used to study 1.4 eV luminescence bands in nominally undoped, nominally stoichiometric CdTe and in donor-compensated, Te-rich CdTe. Combined measurements were made of injection level dependence, transition response and thermal quenching. The 1.4 eV luminescence has the following characteristics: (1) the band shape and peak position are independent of injection level, except for those samples having overlapping bands, (2) the transition is slow, with characteristic times on the order of 1-5E-6 s, (3) the transition response time is approximately constant over three orders of magnitude in doping level, (4) the luminescence intensity increases with donor doping level, and (5) the luminescence shows thermal quenching with a relatively large activation energy. This combination of characteristics is not explicable in terms of well-understood transition mechanisms. It is shown that the contradictory conclusions of previous investigators regarding the nature of the 1.4 eV transitions in CdTe arose from the fact that this transition is of a more complex nature than generally appreciated.
Individual Pitch Control for Wind Turbine Load Reduction Including Wake Modeling

This paper presents an investigation on improving individual pitch control (IPC) for wind turbine load reduction for Region 3 operation with the wake interaction included under the context of wind farm operation. The Larsen wake model is applied for composing the rotor wind profile for downstream turbines under wake interaction, and the simple Jensen model is also described for comparison. The switched controllers were then designed based on the composite wind profile. The wind profile of the turbine wake was generated by modifying the NREL's TurbSim codes. The state-space models of wind turbine were obtained via linearization of wind turbine model available in the NREL's FAST. In particular, in order to obtain more accurate state-space models for IPC design, equivalent circular wind profile was generated so as to better determine the local pitch reference. Based on such models, IPC controllers were designed following the disturbance accommodating control (DAC) and periodic control framework for load redu...
Primary Amine, Thiourea-Based Dual Catalysis Motif for Synthesis of Stereogenic, All-Carbon Quaternary Center-Containing Cycloalkanones

The enantioselective synthesis of α,α-disubstituted cycloalkanones has been developed using a primary amine, thiourea-based dual catalysis pathway. A range of electrophiles and ring sizes are tolerated under the reaction conditions. A possible catalytic cycle is presented to explain the reactivity.
Potential level-lowering for GSp(4)

In this article, we explore a beautiful idea of Skinner and Wiles [SW] in the context of GSp(4) over a totally real field. The main result provides congruences between automorphic forms which are Iwahori-spherical at a certain place w, and forms with a tamely ramified prinicpal series at w. Thus, after base change to a finite solvable totally real extension, one can often lower the level at w. For the proof, we first establish an analogue of the Jacquet-Langlands correspondence, using the stable trace formula. The congruences are then obtained on inner forms, which are compact at infinity modulo the center, and split at all the finite places. The crucial ingredient allowing us to do so, is an important result of Roche [Roc] on types for principal series representations of split reductive groups. 2
Transitions in affirmative action

Abstract A social preference for proportional (or simply increased) participation of minorities in labor markets implies a transition from a regime of segregation (intentional or not) to one of proportional (or increased) participation. In this paper we examine this transition in a formal model of a minority, an employer and an educator. We use the implications of our model to appraise the legal responses to unintentional discrimination, using examples primarily from gender discrimination. The law is found to inhibit this transition, to prevent operation of its own provisions favoring minorities in cases of past discrimination, to ignore means other than the elimination of structural discrimination for increasing minority participation, to prevent coordination of educators and employers that could further policy goals, and to prevent agreements that would provide the public good of integration.
The stars of low luminosity.

Abstract A search has been made among the faint stars with large proper motion found on the Palomar Survey plates for objects that, statistically—judging from their magnitude, color, and proper motion—would appear to be fainter than one ten-thousandth of the sun's luminosity. A total of 122 such objects have been found, and an analysis made for solar motion among them does, indeed, indicate that they must be of exceedingly low luminosity.
RENORMALIZATION IN SPHERICAL FIELD THEORY

Abstract We derive several results concerning non-perturbative renormalization in the spherical field formalism. Using a small set of local counterterms, we are able to remove all ultraviolet divergences in a manner such that the renormalized theory is finite and translationally invariant. As an explicit example we consider massless φ 4 theory in four dimensions.
Congressional committee hearings

Abstract Committees are the instruments through which Congress chooses to screen and process proposals to change public policy. A committee decision to hold hearings, except for the annual appropriations and budget process, indicates a matter has crossed the threshold of political salience. These proceedings serve to focus public and political attention and may be a prelude or an alternative to legislation. This article explores the multipurpose nature of hearings, examines their structure and procedure, and discusses their contents. The aim is to offer a framework within which to analyze and assess the printed product.
Peg-solitaire, string rewriting systems and finite automata

We consider a class of length-preserving string rewriting systems and show that the set of encodings of pairs of strings 〈s, f〉 such that f can be derived from s using the rewriting rules can be accepted by finite automata. As a consequence, we show the existence of a linear time algorithm for determining the solvability of a given k × n peg-solitaire board, for any fixed k. This result is in contrast to the results of (13) and (1) that the same problem is NP-hard for n × n boards. We look at some related string rewriting systems and find conditions under which the encodings of the pairs 〈s,f〉 where f can be derived from s is regular.
Specifying and enforcing high-level semantic obligation policies

Obligation policies specify management actions that must be performed when a particular kind of event occurs and certain conditions are satisfied. Large scale distributed systems often produce event streams containing large volumes of low-level events. In many cases, these streams also contain multimedia data (consisting of text, audio or video). Hence, a key challenge is to allow policy writers to specify obligation policies based on high-level events, that may be derived after performing appropriate processing on raw, low-level events. In this paper, we propose a semantic obligation policy specification language called Eagle, which is based on patterns of high-level events, represented as RDF graph patterns. Our policy enforcement architecture uses a compiler that builds a workflow for producing a stream of events, which match the high-level event pattern specified in a policy. This workflow consists of a number of event sources and event processing components, which are described semantically. We present the policy language and enforcement architecture in this paper.
Generalized dimensional analysis

Abstract I give a simple qualitative derivation and interpretation of a generalization of so-called naive dimensional analysis, a rule for estimating the sizes of terms in an effective theory below the scale of chiral symmetry breaking induced by a strong gauge interaction. The generalization includes the well known N c dependence of ƒ π as a special case but I suggest that it also applies to situation very unlike QCD.
The crystal commutor and Drinfeld's unitarized R-matrix

Drinfeld defined a unitarized R-matrix for any quantum group $U_{q}(\mathfrak {g})$ . This gives a commutor for the category of $U_{q}(\mathfrak {g})$ representations, making it into a coboundary category. Henriques and Kamnitzer defined another commutor which also gives $U_{q}(\mathfrak {g})$ representations the structure of a coboundary category. We show that a particular case of Henriques and Kamnitzer's construction agrees with Drinfeld's commutor. We then describe the action of Drinfeld's commutor on a tensor product of two crystal bases, and explain the relation to the crystal commutor.
Big Bang Nucleosynthesis and a New Approach to Galactic Chemical Evolution

Big bang production of deuterium is the best indicator of the baryon density; however, only the present abundance of D is known (and only locally) and its chemical evolution is intertwined with that of 3He. Because Galactic abundances are spatially heterogeneous, mean chemical-evolution models are not well suited for extrapolating the pre-solar D and 3He abundances to their primeval values. We introduce a new approach which explicitly addresses heterogeneity by statistically tracing the history of the pre-solar material back to its primeval beginning. We show that the decade-old concordance interval η ≈ (2-8) × 10-10 based on D and 3He is well founded.
Separate and combined effects of growth hormone and parathyroid hormone on cortical bone osteopenia in ovariectomized aged rats.

The focus of this study is on whether cortical osteopenia occurs in ovariectomized aged female rats, and if so, whether growth hormone (GH) and parathyroid hormone (PTH) independently or together (GH+PTH) can rebuild the lost cortical bone. Tibio-fibula junction was analyzed by histomorphometry and peripheral quantitative computerized tomography (pQCT) densitometry. Significant loss of cortical bone area (Ct.BAr), cortical bone mineral content (Ct. BMC), cortical thickness (Ct. Th) and increase of endocortical perimeter occurred 4 months after ovariectomy. The rats were given GH, PTH, GH+PTH or vehicle for 2 months and sacrificed. GH, PTH and GH+PTH increased Ct. BAr, Ct. BMC, Ct. Th, periosteal perimeter, periosteal double-labeled perimeter, mineral apposition rate, and bone formation rate, but decreased marrow area. PTH and GH+PTH decreased endocortical perimeter, and increased endocortical double labeled perimeter and bone formation rate. In conclusion, ovariectomy induced cortical bone loss in aged rats by increasing endocortical bone resorption. Growth hormone increased periosteal bone formation, while PTH stimulated endocortical bone formation and in combination GH+PTH produced complementary effects thereby reversing osteopenia.
On Ramsey equilibrium: capital ownership pattern and inefficiency

We provide a sufficient condition on the production function under which eventually the most patient household owns the entire capital stock in every Ramsey equilibrium, called the turnpike property. This generalizes the result in the literature which establishes the turnpike property using the capital income monotonicity condition. We then provide an example of a Ramsey equilibrium in which the most patient household reaches a no capital position infinitely often. This is a strong refutation of the turnpike property on Ramsey equilibria. We also show that the constructed Ramsey equilibrium is inefficient in terms of the aggregate consumption stream that it provides.
The X-ray Spectrum and Global Structure of the Stellar Wind in VELA X-1

We present a quantitative analysis of the X-ray spectrum of the eclipsing high mass X-ray binary Vela X-1 (4U 0900-40) using archival data from the ASCA Solid-State Imaging Spectrometer. The observation covers a time interval centered on the eclipse of the X-ray pulsar by the companion. The spectrum exhibits two distinct sets of discrete features: (1) recombination lines and radiative recombination continua from mostly hydrogenic and helium-like species produced by photoionization in an extended stellar wind; and (2) fluorescent K-shell lines associated with near-neutral species also present in the circumsource medium. These features are superposed on a faint continuum, which is most likely nonthermal emission from the accreting neutron star that is scattered into our line of sight by free electrons in the wind. Using a detailed spectral model that explicitly accounts for the recombination cascade kinetics for each of the constituent charge states, we are able to obtain a statistically acceptable (χ = 0.88) fit to the observed spectrum and to derive emission measures associated with the individual K-shell ions of several elements. From calculations of the ionization balance using the photoionization code, XSTAR, we assign ionization parameters, ξ, to several ions, and construct a differential emission measure (DEM) distribution. The DEM distribution spans a broad range in ξ (Δ log ξ 2) and is centered around log ξ = 2.5. We find that the total emission measure of the visible portion of the highly ionized wind is ~3 × 1056 cm-3. The qualitative aspects of the inferred DEM distribution are consistent with a wind model derived from the Hatchett & McCray picture of an X-ray source immersed in a stellar wind with a generalized Castor, Abbott, & Klein velocity profile. Using this formalism, theoretical DEM distributions, parameterized only by a mass-loss rate and a wind velocity profile, are calculated and used to predict the detailed X-ray spectrum, which is then compared to the ASCA data. Again, we find a statistically acceptable fit (χ = 1.01), with a best-fit mass-loss rate of ~2.7 × 10-7 M☉ yr-1. This is approximately a factor of 10 lower than previous estimates of the mass-loss rate for the Vela X-1 companion star, which have primarily been determined from C IV and Si IV P Cygni profiles, and X-ray absorption measurements. We argue that this discrepancy can be reconciled if the X-ray-irradiated portion of the wind in Vela X-1 is structurally inhomogeneous, consisting of hundreds of cool, dense clumps embedded in a hotter, more ionized gas. Most of the mass is contained in the clumps, while most of the wind volume (>95%) is occupied by the highly ionized component. We show quantitatively that this interpretation is also consistent with the presence of the X-ray fluorescent lines in the ASCA spectrum, which are produced in the cooler, clumped component.
Predicting single-neuron activity in locally connected networks

The characterization of coordinated activity in neuronal populations has received renewed interest in the light of advancing experimental techniques that allow recordings from multiple units simultaneously. Across both in vitro and in vivo preparations, nearby neurons show coordinated responses when spontaneously active and when subject to external stimuli. Recent work (Truccolo, Hochberg, & Donoghue, 2010) has connected these coordinated responses to behavior, showing that small ensembles of neurons in arm-related areas of sensorimotor cortex can reliably predict single-neuron spikes in behaving monkeys and humans. We investigate this phenomenon using an analogous point process model, showing that in the case of a computational model of cortex responding to random background inputs, one is similarly able to predict the future state of a single neuron by considering its own spiking history, together with the spiking histories of randomly sampled ensembles of nearby neurons. This model exhibits realistic cortical architecture and displays bursting episodes in the two distinct connectivity schemes studied. We conjecture that the baseline predictability we find in these instances is characteristic of locally connected networks more broadly considered.
Far-infrared Properties of Lyman Break Galaxies from Cosmological Simulations

Utilizing state-of-the-art adaptive mesh refinement cosmological hydrodynamic simulations with ultra-high resolution (114 h{sup -1} pc) and a large sample size ({>=}3300 galaxies of stellar mass {>=}10{sup 9} M{sub Sun }), we show how the stellar light of Lyman break galaxies at z = 2 is distributed between optical/ultraviolet (UV) and far-infrared (FIR) bands. With a single scalar parameter for dust obscuration we can simultaneously reproduce the observed UV luminosity function for the entire range (3-100 M{sub Sun} yr{sup -1}) and extant FIR luminosity function at the bright end ({>=}20 M{sub Sun} yr{sup -1}). We quantify that galaxies more massive or having higher star formation rate (SFR) tend to have larger amounts of dust obscuration mostly due to a trend in column density and in a minor part due to a mass (or SFR)-metallicity relation. It is predicted that the FIR luminosity function in the range SFR = 1-100 M{sub Sun} yr{sup -1} is a power law with a slope of about -1.7. We further predict that there is a 'galaxy desert' at SFR{sub FIR} < 0.02(SFR{sub UV}/10 M{sub Sun} yr{sup -1}){sup 2.1} M{sub Sun} yr{sup -1} in the SFR{sub UV} - SFR{sub FIR} plane. Detailed distributions of SFR{sub FIR} atmore » a fixed SFR{sub UV} are presented. Upcoming observations by the Atacama Large Millimeter Array should test this model. If confirmed, it validates the predictions of the standard cold dark matter model and has important implications on the intrinsic SFR function of galaxies at high redshift.« less
Gold Monetization and Gold Discipline

Gold and its price have emerged as frequent topics of both academic and government debate.2 Public attention, focused on the gold market since gold’s price began fluctuating violently in 1980 and 1981, has turned to gold as a possible means of removing some discretion inherent in the current fiat money system. Since lack of adherence to monetary rules can lead to problems of dynamic policy inconsistency, academic economists have begun seriously to reconsider monetary standards based either on gold or on some other commodity as politically feasible methods of establishing rules.3
Magnetization rotation or generation of incoherent spin waves? Suggestions for a spin-transfer effect experiment.

Abstract “Spin-transfer” torque is created when electric current is passed through metallic ferromagnets and may have interesting applications in spintronics. So far it was experimentally studied in “collinear” geometries, where it is difficult to predict whether magnetization will coherently rotate or spin-waves will be generated. Here we propose an easy modification of existing experiment in which the spin-polarization of incoming current will no longer be collinear with magnetization and recalculate the switching behavior of the device. We expect that a better agreement with the magnetization rotation theory will be achieved. That can be an important step in reconciling alternative points of view on the effect of spin-transfer torque.
CHANDRA GRATING SPECTROSCOPY OF THE Be/X-RAY BINARY 1A 0535+262

We present Chandra HETGS spectroscopy of the Be/X-ray binary 1A 0535+262 obtained during the 2009/2010 giant outburst. These are the first CCD grating spectra of this type of system during a giant outburst. Our spectra reveal a number of lines including a narrow Fe Kα emission line with an FWHM of ~5000 km s–1. For the first time, we detect the presence of a highly ionized outflow in a Be/X-ray binary. Assuming that the line is He-like Fe XXV, fits with a simple Gaussian imply an outflow velocity of ~1500 km s–1. However, self-consistent photoionization modeling with XSTAR suggests that Fe XXIII-XXIV must also contribute. In this case, an outflow velocity of ~3000 km s–1 is implied. These results are discussed in the context of accretion flow in Be-star, neutron star, and black hole X-ray binaries.
The Hausdorff dimension of surfaces in two-dimensional quantum gravity coupled to Ising minimal matter

Abstract Within the framework of string field theory the intrinsic Hausdorff dimension d h of the ensemble of surfaces in two-dimensional quantum gravity has recently been claimed to be 2 m for the class of unitary minimal models ( p = m +1, q = m ). This contradicts recent results from numerical simulations, which consistently find d h ≈ 4 in the cases m = 2, 3, 5 and ∞. The string field calculations rely on identifying the scaling behavior of geodesic distance and area with respect to a common length scale l . This length scale is introduced by formulating the models on a disk with fixed boundary length l . In this paper we study the relationship between the mean area and the boundary length for pure gravity and the Ising model coupled to gravity. We discuss how this relationship is modified by relevant perturbations in the Ising model. We discuss how this leads to a modified value for the Hausdorff dimension.
Mobile communications satellite antenna flight experiment definition

Results of a NASA-sponsored study to determine the technical feasibility and cost of a Shuttle-based flight experiment specifically intended for the MSAT commercial user community are presented. The experiment will include demonstrations of technology in the areas of radio frequency, sensing and control, and structures. The results of the structural subsystem study summarized here include experiment objective and technical approach, experiment structural description, structure/environment interactions, structural characterization, thermal characterization, structural measurement system, and experiment functional description.
The RHESSI Microflare Height Distribution

We present the first in-depth statistical survey of flare source heights observed by RHESSI. Flares were found using a flare-finding algorithm designed to search the 6-10 keV count-rate when RHESSI's full sensitivity was available in order to find the smallest events (Christe et al., 2008). Between March 2002 and March 2007, a total of 25,006 events were found. Source locations were determined in the 4-10 keV, 10-15 keV, and 15-30 keV energy ranges for each event. In order to extract the height distribution from the observed projected source positions, a forward-fit model was developed with an assumed source height distribution where height is measured from the photosphere. We find that the best flare height distribution is given by g (h) oc exp(-h/lambda) where lambda = 6.1 plus or minus 0.3 Mm is the scale height. A power law height distribution with a negative power law index, gamma = 3.1 plus or minus 0.3 is also consistent with the data. Interpreted as thermal loop top sources, these heights are compared to loops generated by a potential field model (PFSS). The measured flare heights distribution are found to be much steeper than the potential field loop height distribution which may be a signature of the flare energization process.
Null synthesis with phase and amplitude controls at the subarray outputs

The generation of nulls in an antenna pattern by controlling the phase and amplitude of the subarray output signals is investigated. Although the nulls may be formed with any number of subarrays, the subarray configuration and desired null location have a major impact on the distortion in the far-field pattern that results. The distortion problem resulting from subarray nulling is well-known, but little theoretical analysis has been done to explain the cause of the distortion. A theoretical and graphical explanation of why the distortion occurs is offered.
JMB: scaling wireless capacity with user demands

We present JMB, a joint multiuser beamforming system, that enables independent access points (APs) to beamform their signals and communicate with their clients on the same channel as if they were one large MIMO transmitter. The key enabling technology behind JMB is a new low-overhead technique for synchronizing the phase of multiple transmitters in a distributed manner. The design allows a wireless LAN to scale its throughput by continually adding more APs on the same channel. JMB is implemented and tested with both software radio clients and off-the-shelf 802.11n cards, and evaluated in a dense congested deployment resembling a conference room. Results from a 10-AP software-radio testbed show a linear increase in network throughput with a median gain of 8.1--9.4×. Our results also demonstrate that JMB's joint multiuser beamforming can provide throughput gains with unmodified 802.11n cards.
Melting in the deep upper mantle oceanward of the Honshu slab

Abstract We examine the upper mantle and transition zone beneath the western Pacific using multiple ScS reverberations. A low-velocity zone (LVZ) is found above the 410-km discontinuity oceanward of the subducting Honshu slab at an average depth of 356 km, with a thickness that ranges from 50 to 75 km assuming the LVZ continues to the 410-km discontinuity, which is locally elevated. The low-velocity region is evident in previous tomographic studies, and our results suggest that the anomaly is best explained by a layer of partial melt. The layer may be entrained from above by subduction or produced in situ by the combined effects of water and temperature. A self-consistent model that explains local P-wave velocities (Obayashi, M., Sugioka, H., Yoshimitsu, J., Fukao, Y., 2006. High temperature anomalies oceanward of subducting slabs at the 410-km discontinuity. Earth and Planetary Science Letters 243, 149–158) and our observations calls for a maximum temperature anomaly of ∼150 °C and a resulting maximum olivine water content after melting of 0.100 wt. %.
Institutions and Bribery in an Authoritarian State

Scholars have suggested that corruption could serve as a substitute for property-protecting institutions in developing countries, but very few empirical studies have been conducted to test this theory. Most existing studies on the determinants of corruption are cross-national, rely on perception-based measures, and focus on economic development, regime type, and market structure as explanatory variables. Little is known about why corruption occurs in an authoritarian state at the micro level. We theorize bribery as a bargaining process between a firm and a rent-maximizing public official, and we assume that graft-paying firms face different sets of rules and regulations, which govern firms' costs and benefits of bribing. We test the hypothesis that firms' bribes are determined by the rigor of their internal auditing control and the quality of property-protecting institutions. We use entertainment and travel costs directly observed in a large-scale firm-level survey in China as a proxy for corruption. Our study implies that firms operating in a weak property rights regime rely on political connections as a substitute for formal legal protection. The findings shed light on the literature on property rights, corruption, and East Asian development.
On the Evolution of U.S. Trade Agreements: Evidence from Taussig's Tariff Commission

The first chairman of the U.S. Tariff Commission, Frank W. Taussig, expected the new body to put an end to "haphazard" and "irresponsible" management of trade policy. Reforming trade agreements was a top priority. In 1922, acting on the Commission's weighty report, Reciprocity and Commercial Treaties (1919), the State Department initiated a trade-agreements policy centered on the unconditional form of the most-favored-nation (MFN) principle. But after observing the program for a decade, Taussig urged that "the whole present policy should be scrapped." This essay examines the evolution of U.S. trade agreements from 1919 to 1932 and the reasons for Taussig's disaffection.
The Displacement and Split Decompositions for a Q-Polynomial Distance-regular Graph

Let Γ denote a Q-polynomial distance-regular graph with diameter at least three and standard module V. We introduce two direct sum decompositions of V. We call these the displacement decomposition for Γ and the split decomposition for Γ. We describe how these decompositions are related.
Transannular aldol condensations within macrocyclic lactones: A novel approach to 8-membered carbocyclic rings.

Abstract A novel method has been developed for the construction of 8-membered carbocyclic rings, involving as the key step a chemoselective transannular aldol condensation within an 11-membered ketolactone ring.
Singletons, doubletons and M-theory

Abstract We identify the two-dimensional AdS subsupergroup OSp( 16 2 , R ) of the M-theory supergroup OSp( 1 32 , R ) which captures the dynamics of n DO-branes in the large n limit of Matrix theory. The Sp(2, R ) factor in the even subgroup SO(16) x Sp(2, R ) of OSp( 16 2 , R ) corresponds to the AdS extension of the Poincare symmetry of the longitudinal directions. The infinite number of D0-branes with ever increasing and quantized values of longitudinal momenta are identified with the Fourier modes of the singleton supermultiplets of OSp( 16 2 , R ) , which consist of 128 bosons and 128 fermions. The large n limit of N = 16 U(n) Yang-Mills quantum mechanics which describes Matrix theory is a conformally invariant N = 16 singleton quantum mechanics living on the boundary of AdS2. We also review some of the earlier results on the spectra of Kaluza-Klein supergravity theories in relation to the recent conjecture of Maldacena relating the dynamics of n Dp-branes to certain AdS supergravity theories. We point out the remarkable parallel between the conjecture of Maldacena and the construction of the spectra of l 11d and type IIB supergravity theories compactified over various spheres in terms of singleton or doubleton supermultiplets of corresponding AdS supergroups.
Access to and penetration of ICT in rural Thailand

This paper presents an econometric study of information and communication technology (ICT) in all 70,000 rural villages in Thailand, where the ICT considered consists of fixed-line telephone service, mobile telephone service, public telephones, computers, and Internet service. The results may provide information that helps policymakers decide where to put limited resources to promote ICT, and helps profit-seeking ICT companies target regions that maximize revenues. The study found that education is far more important than income in predicting the percentage of households who adopt ICT services, and that some unexpected variables such as the penetration of pickup trucks are useful predictors as well. Even in areas where fixed-line phone service is available, 70% of households with computers choose not to become Internet subscribers, although many presumably have enough money and technical knowledge. By separating availability from penetration of ICT, the study found that they can have different predictors, which means that researchers who do not separate them may get misleading results. There is no evidence showing mobile telephone service as a substitute for fixed-line telephone service. Also, public telephone service had little or no impact as a substitute for fixed-line or mobile telephone service, so phone companies need not fear that deployment of more public telephones will decrease their subscribership. Finally, there appears to be significant unmet demand for telephone service in rural Thailand where the infrastructure does not yet exist.
Experimental Investigation of Fluctuations in a Nonequilibrium MHD Plasma

The electrical fluctuations in an argon-potassium nonequilibrium plasma have been studied over a wide range of Hall parameter and electron-to-gas temperature ratios. For electron densities above 2 X 10 cm", the fluctuations increase greatly in intensity as the Hall parameter exceeds a critical value. The variation of the critical value with electron temperature is in accord with the electrothermal wave stability theory. For electron densities below 2 X 10, the behavior of the fluctuations seems in accord with the theory of magnetoacoustic waves except that the theoretically predicted growth rates seem too small to explain the measured amplitudes. The transition at an electron density of 2 X 10 is probably due to the reduced ionization rate, which limits the growth rate of electrothermal waves. Substantial reductions of effective conductivity and Hall parameter are associated with the fluctuations for both high and low electron densities, at large Hall parameter, although the reduction is greatest at large electron densities.
A Model and the Methodology for Determining Wear Particle Generation Rate and Filter Efficiency in a Diesel Engine Using Ferrography

Abstract A mathematical model was developed that describes the wear particle concentration as a function of time in a diesel engine. This model contains engine and lubrication system parameters that determine the concentration of wear particles in the engine sump. These variables are the oil system volume, oil flow rate, particle generation rate, filtering efficiency and the initial particle concentration. The model was employed to study the wear particle concentrations in the sump and the mass of particles in the filter for the Cummins VT-903 diesel engine. In addition, the model was used to develop a testing methodology for determining wear particle generation rates and filter efficiencies from used oil analysis. This testing methodology uses ferrography together with computer programs to yield accurate statistical information on the data as curve fitted to the model. The test set-up incorporated a remote-controlled sampling system that enabled the accurate and periodic taking of oil samples over an engine test approximately 5 h in duration. Results of this research indicate that equilibrium wear particle concentrations increase with an increase in engine speed and load. The wear particle generation rate and filter efficiency as determined by the test methodology were found to decrease with an increase in engine speed and load. After oil and filter changes, the wear particle generation rate and filter efficiency continually increased with cumulative engine time up to approximately 11 h. The test methods used to obtain the results above were found to be repeatable to within ±15% and could conceivably be employed to determine wear parameters on other diesel engines as well as the effects that other engine variables such as lubricants, oil temperature, coolant temperature and engine components have on the wear parameters.
On radiative cooling and temperature profiles of counterflow premixed flames

Abstract Axial and radial temperature profiles of the gaseous slab in between two symmetric counterflow premixed flames of methane are measured. The results indicate that for widely separated lean and rich flames, there exists a temperature dip which is accounted for on the basis of radiative heat loss. For lean flames, the dependence of the temperature dip on the flame separation distance, and hence volume of the emitting gas, is determined. The calculated total radiant loss from the transparent gas volume, based on CO 2 H 2 O emissivities obtained from Hottel's curves, results in average temperature drops which closely agree with the measured values. The data are also in favorable agreement with the previously developed theory for radiatively cooled counterflow premixed flames. Also reported is the influence of the thermocouple coating thickness on the measured temperatures. Potential application of the present experimental method to the evaluation of effective emissivities of luminous and nonluminous slabs of combustion products of different fuels is discussed.
Palladium-Catalyzed Asymmetric Allylic Alkylation of 2-Acylimidazoles as Ester Enolate Equivalents

A broad range of highly enantioenriched 2-acylimidazoles are synthesized by palladium-catalyzed decarboxylative asymmetric allylic alkylation (DAAA) of 2-imidazolo-substituted enol carbonates. The enantioenriched 2-acylimidazole products can easily be converted to the corresponding carboxylic acid, ester, amide, and ketone derivatives with complete retention of the enantiopurity. The synthetic utility of this new method is demonstrated in the short, efficient synthesis of cetiedil.
Fully integrated aerodynamic/dynamic optimization of helicopter rotor blades

This paper describes a fully integrated aerodynamic/dynamic optimization procedure for helicopter rotor blades. The procedure combines performance and dynamics analyses with a general purpose optimizer. The procedure minimizes a linear combination of power required (in hover, forward flight, and maneuver) and vibratory hub shear. The design variables include pretwist, taper initiation, taper ratio, root chord, blade stiffnesses, tuning masses, and tuning mass locations. Performance constraints consist of limits on power required in hover, forward flight, maneuver, airfoil section stall, drag-divergence Mach number, minimum tip chord, and trim. Dynamic constraints are on blade natural frequencies, minimum autorotational inertia, and maximum blade weight. The procedure is demonstrated for two cases. In the first case, the objective function involves power required (in hover, forward flight, and maneuver) and vibratory hub shear. In the second case, the objective function involves power required in hover and vibratory hub shear. For both cases, the designs from the integrated procedure are compared with designs from a sequential optimization approach. In the sequential optimization approach, the blade is optimized first for performance (minimum power) using only aerodynamic design variables and performance constraints. Then these optimized aerodynamic design variables are held fixed, and the blade is optimized for minimum vibratory hub shear, using only dynamic design variables and dynamic constraints. In both cases, the integrated approach is superior to the sequential approach.
Control Architecture Study Focused on Energy Savings of an Aircraft Thermal Management System

The next generation of aircraft will face more challenging demands in both electrical and thermal loads. The larger thermal loads reduce the propulsion system efficiency by demanding bleed air from the main engine compressor or imposing a shaft load on the high or low pressure shaft. The approach adopted to power the thermal management system influences the overall fuel burn of the aircraft for a given mission. To assess these demands and to explore conceptual designs for the electrical and thermal management system, a dynamic vehicle level tip-to-tail (T2T) model has been developed. The T2T model captures and quantifies the energy exchanges throughout the aircraft. The following subsystems of the aircraft are simulated in the T2T model: Air vehicle system, propulsion system, adaptive power thermal management system, fuel thermal management system, electrical system and actuator system. This paper presents trade studies of the impact of various approaches in power take-off from the main engine and control strategies. The trade studies identify different control strategies resulting in significant fuel savings for a given mission profile.Copyright © 2013 by ASME
THE BUTCHER-OEMLER EFFECT AT MODERATE REDSHIFT

We present the results of Butcher-Oemler–style analysis of three moderate-redshift (0.1 < z < 0.2) clusters that have bimodal X-ray surface brightness profiles. We find that at least two of these clusters exhibit unusually high fractions of blue galaxies (fb's) as compared with clusters at comparable redshifts studied by Butcher & Oemler. This implies that star formation is occurring in a high fraction of the galaxies in the two clusters. Our results are consistent with hierarchical clustering models in which subcluster-subcluster mergers create shocks in the intracluster medium. The shocks, in turn, induce simultaneous starbursts in a large fraction of cluster galaxies. Our study therefore lends weight to the hypothesis that the Butcher-Oemler effect is an environmental, as well as evolutionary, phenomenon.
Non-Commutative Carathéodory Interpolation

We prove a Caratheodory–Fejer type interpolation theorem for certain matrix convex sets in \({\mathbb{C}^d}\) using the Blecher–Ruan–Sinclair characterization of abstract operator algebras. Our results generalize the work of Dmitry S. Kalyuzhnyĭ-Verbovetzkiĭ for the d-dimensional non-commutative polydisc.
Do transient storage parameters directly scale in longer, combined stream reaches? Reach length dependence of transient storage interpretations

Summary Little work has been done to assess parameterizations and related interpretations (i.e., metrics of exchange) of transient storage modeling (TSM) over multiple spatial scales in streams. In this paper, we simulate conservative solute transport in a small mountain stream over combinations of five consecutive sub-reaches (38 m, 105 m, 281 m, 433 m, and 619 m below injection point) to (1) determine how optimized parameter estimates vary with reach length and reach combination, and (2) evaluate whether equally well-optimized simulations of solute transport in the channel result in varying interpretations of tracer exchange with the storage zone. Each simulated stream solute concentration breakthrough curve (BTC) showed consistently accurate fits to observations. However, our results indicate approximate equifinality (similar fits from different parameter sets) in the simulations of concentrations of stream tracer across individual sub-reaches and combined reaches leading to varying interpretations of transient storage exchange parameterization (i.e., variable optimized parameter estimates) and concentration time series of tracer in the storage zone. These results suggest strong reach-length dependence in simulated exchange. Based on stream BTCs alone, the TSM is useful in characterizing the influence of transient storage on in-stream solute transport, though it does not consistently reproduce storage zone dynamics. Characterization of the solute exchange between the stream and the storage zones remains problematic, and the effects of transient storage cannot be directly compared within overlapping stream reaches, an important consideration in designing and interpreting stream solute transport experiments.