cssi/SciSciGPT-SciSciNet huggingface dataset:
Adapting Contract Theory to Fit Contract Farming

This article discusses the current state of contract theory and its usefulness for conceptualizing issues related to agricultural contracting. I will discuss the limitations of existing theory for applied work, and what methodological improvements are needed to enhance the usefulness of the theory to agricultural economists. One pervasive problem is that the canonical economic literature on contracts is rather fragmented and the various methodological strands are narrow in their focus. As such, there is a need for agricultural economists to engage in methodological research to develop applied contracting models that can capture higher order features of real world agricultural contracts while delivering generalizable comparative statics predictions. The need for such research is obvious as contracting continues to expand along the entire modern food marketing channel. In the latter part of this article, I develop a simple model to illustrate how classic methodological approaches can be combined with recent developments in contract and game theory to construct applied theory models that are useful for capturing some important features of agricultural contracts.
The Catalytic Oxidative Coupling of Methane

One of the great challenges in the field of heterogeneous catalysis is the conversion of methane to more useful chemicals and fuels. A chemical of particular importance is ethene, which can be obtained by the oxidative coupling of methane. In this reaction CH4 is first oxidatively converted into C2H6, and then into C2H4. The fundamental aspects of the problem involve both a heterogeneous component, which includes the activation of CH4 on a metal oxide surface, and a homogeneous gas-phase component, which includes free-radical chemistry. Ethane is produced mainly by the coupling of the surface-generated CH radicals in the gas phase. The yield of C2H4 and C2H6 is limited by secondary reactions of CH radicals with the surface and by the further oxidation of C2H4, both on the catalyst surface and in the gas phase. Currently, the best catalysts provide 20% CH4 conversion with 80% combined C2H4 and C2H6 selectivity in a single pass through the reactor. Less is known about the nature of the active centers than about the reaction mechanism; however, reactive oxygen ions are apparently required for the activation of CH4 on certain catalysts. There is spectroscopic evidence for surface O− or O ions. In addition to the oxidative coupling of CH4, cross-coupling reactions, such as between methane and toluene to produce styrene, have been investigated. Many of the same catalysts are effective, and the cross-coupling reaction also appears to involve surface-generated radicals. Although a technological process has not been developed, extensive research has resulted in a reasonable understanding of the elementary reactions that occur during the oxidative coupling of methane.
Net field-aligned currents observed by Triad

From the Triad magnetometer observation of a step-like level shift in the east-west component of the magnetic field at 800 km altitude, the existence of a net current flowing into or away from the ionosphere in a current layer was inferred. The current direction is toward the ionosphere on the morning side and away from it on the afternoon side. The field aligned currents observed by Triad are considered as being an important element in the electro-dynamical coupling between the distant magnetosphere and the ionosphere. The current density integrated over the thickness of the layer increases with increasing magnetic activity, but the relation between the current density and Kp in individual cases is not a simple linear relation. An extrapolation of the statistical relation to Kp = 0 indicates existence of a sheet current of order 0.1 amp/m even at extremely quiet times. During periods of higher magnetic activity an integrated current of approximately 1 amp/m and average current density of order 0.000001 amp/sq m are observed. The location and the latitudinal width of the field aligned current layer carrying the net current very roughly agree with those of the region of high electron intensities in the trapping boundary.
Dynamic imaging by model estimation

This article presents a model-based method for dynamic magnetic resonance imaging. This method models the time variation of an object by a generalized harmonic model, thus converting the dynamic imaging problem to a parameter identification problem. Experimental results are shown to demonstrate that this method is able to produce high-resolution time-sequential images from a dynamic object with periodic or quasi-periodic time variations. © 1997 John Wiley & Sons, Inc. Int J Imaging Syst Technol, 8, 551–557, 1997
Home Country Networks and Foreign Expansion: Evidence from the Venture Capital Industry

We propose that home country network advantages shape firms' foreign expansion. We argue that a social status advantage is transferable from one market to another as a signal of quality but that a ...
Perspectives in Modeling: Simulation, Database, and Workflow

Development of today's advanced applications is increasingly being accomplished using multi-faceted modeling. For example, the areas of simulation and workflow modeling generally need data modeling as a foundational capability. In addition, simulation modeling and workflow modeling can be used together, synergistically. Based on the experience of the LSDIS group in developing systems and models, we have found that establishing rich linkages between disparate models works better than having one comprehensive unified model. In addition, we agree with the consensus that two dimensional models are generally considered to be easier to create and understand than one dimensional models. Furthermore, just as richly linked text is referred to as hyper-text, richly linked diagrams may be referred to as hyper-diagrams. Two modeling toolkits, METEOR Designer and the JSIM Modeling Toolkit, illustrate the advantages of using such approaches.
Diagnostic Yield of Electroencephalography in a General Inpatient Population

Objective: To determine the frequency and clinical predictors of seizures and markers of epileptiform activity in a non-critically ill general inpatient population. Patients and Methods: We performed a retrospective cohort study of patients 18 years and older who underwent inpatient electroencephalography (EEG) between January 1, 2005, and December 31, 2010, for an indication of spells or altered mental status. The EEGs and reports were reviewed for ictal activity, interictal epileptiform abnormalities, and nonepileptiform abnormalities. Demographie and clinical data were gathered from the electronic medical record to determine seizure predictors. Results: Of 2235 patients screened, 1048 met the inclusion criteria, of which 825 (78.7%) had an abnormal EEG finding. Seizures occurred in 78 of 1048 patients (7.4%), and interictal epileptiform discharges were noted in 194 of 1048 patients (18.5%). An intracranial mass and spells as the indication for the EEG were independently associated with the group of pat...
Robust adaptive controller with zero residual tracking errors

The adaptive control of a plant whose dominant part has transfer function with relative degree n^{\ast} = 1 has been considered in the presence of parasitics and disturbances. A new adaptive law is proposed which guarantees the existence of a large region of attraction from which all signals are bounded and the tracking error converges to a small residual set. In contrast to the adaptive law used in [1], [2] the new adaptive law guarantees a smaller residual set for the tracking error, which reduces to zero when the parasitics and disturbances disappear.
A Novel Three-Dimensional Contact Finite Element Based on Smooth Pressure Interpolations

This article proposes a new three-dimensional contact finite element which employs continuous and weakly coupled pressure interpolations on each of the interacting boundaries. The resulting formulation circumvents the geometric bias of one-pass methods, as well as the surface locking of traditional two-pass node-on-surface methods. A Lagrange multiplier implementation of the proposed element is validated for frictionless quasi-static contact by a series of numerical simulations. Published in 2001 by John Wiley & Sons, Ltd.
π-Face selective azaspirocyclization of ω-(methoxyphenyl)-N-methoxyalkylamides

A novel method for the stereoselective preparation of 1-azaspiranes is described. Treatment of α- and β-substituted 3-(methoxyphenyl)-N-methoxypropionamides 1 with phenyliodine(III) bis(trifluoroacetate) initiates efficient azaspirocyclization, via a putative N-acylnitrenium ion intermediate, to provide cyclohexa-2,5 and 2,4-dienone spirolactams 8 and 11 with good π-facial selectivity. Furthermore, a preliminary study indicates that this strategy is also amenable to the preparation of 1-azaspiro[5.5]undeca-2,5-dienones.
To the quantum limitations in beam physics

The conditions reviewed for degeneration in an electron bunch treated as a Fermi gas. Some comparison made for photoinjectors and storage rings. In some cases quantum limitations are very close.
Authentication with distortion criteria

In a variety of applications, there is a need to authenticate content that has experienced legitimate editing in addition to potential tampering attacks. We develop one formulation of this problem based on a strict notion of security, and characterize and interpret the associated information-theoretic performance limits. The results can be viewed as a natural generalization of classical approaches to traditional authentication. Additional insights into the structure of such systems and their behavior are obtained by further specializing the results to Bernoulli and Gaussian cases. The associated systems are shown to be substantially better in terms of performance and/or security than commonly advocated approaches based on data hiding and digital watermarking. Finally, the formulation is extended to obtain efficient layered authentication system constructions.
GPU-accelerated multi-valued solid voxelization by slice functions in real time

This paper presents a GPU-accelerated slice-independent solid voxelization approach that utilizes a dynamic slice function mechanism and masking techniques to significantly improve solid voxelization speed in real time as well as create various multi-valued solid volumetric models with different slice functions. In particular, by dynamically applying different slice functions, any surface-closed geometric model can be voxelized into a solid volumetric representation with any kind of interior materials, such as rainbow, marble, wood, translucent jade, etc. In this paper, the design of the dynamic slice function, the principle and algorithm of solid slice creation, the algorithm of real-time solid voxelization, and GPU-based acceleration techniques will be discussed in detail. The algorithms introduced in this paper are easy to implement and convenient to integrate into many applications, such as volume modeling, collision detection, medical simulation, volume animation, volume deformation, 3D printing, and computer art. The experimental results and data analysis for the complex objects demonstrate the effectiveness, flexibility, and diversity of this approach.
Passive control of discrete-frequency tones generated by coupled detuned cascades

Abstract Discrete-frequency tones generated by rotor–stator interactions are of particular concern in the design of fans and compressors. Classical theory considers an isolated flat-plate cascade of identical uniformly spaced airfoils. The current analysis extends this tuned isolated cascade theory to consider coupled aerodynamically detuned cascades where aerodynamic detuning is accomplished by changing the chord of alternate rotor blades and stator vanes. In a coupled cascade analysis, the configuration of the rotor influences the downstream acoustic response of the stator, and the stator configuration influences the upstream acoustic response of the rotor. This coupled detuned cascade unsteady aerodynamic model is first applied to a baseline tuned stage. This baseline stage is then aerodynamically detuned by replacing alternate rotor blades and stator vanes with decreased chord airfoils. The nominal aerodynamically detuned stage configuration is then optimized, with the stage acoustic response decreased 13 dB upstream and 1 dB downstream at the design operating condition. A reduction in the acoustic response of the optimized aerodynamically detuned stage is then demonstrated over a range of operating conditions.
Moment-based spectral analysis of large-scale networks using local structural information

The eigenvalues of matrices representing the structure of large-scale complex networks present a wide range of applications, from the analysis of dynamical processes taking place in the network to spectral techniques aiming to rank the importance of nodes in the network. A common approach to study the relationship between the structure of a network and its eigenvalues is to use synthetic random networks in which structural properties of interest, such as degree distributions, are prescribed. Although very common, synthetic models present two major flaws: 1) These models are only suitable to study a very limited range of structural properties; and 2) they implicitly induce structural properties that are not directly controlled and can deceivingly influence the network eigenvalue spectrum. In this paper, we propose an alternative approach to overcome these limitations. Our approach is not based on synthetic models. Instead, we use algebraic graph theory and convex optimization to study how structural properties influence the spectrum of eigenvalues of the network. Using our approach, we can compute, with low computational overhead, global spectral properties of a network from its local structural properties. We illustrate our approach by studying how structural properties of online social networks influence their eigenvalue spectra.
Slag and Thermal Environment of a Spinning Rocket Motor

Abstract : It has been demonstrated that an increase in radial and/or axial acceleration results in an increase in the amount of slag accumulated in the chamber of a motor with a submerged nozzle design. The slag is composed of aluminum and alumina residue from the combustion of aluminized solid propellants. The presence of slag in the chamber influences motor burnout weight, soak-out thermal environment, residual thrust, and motor performance. An excessive amount of slag in the chamber also could affect mission success. This report studies the effect of slag in the chamber on the motor case thermal environment of a spinning rocket motor. Very good agreement between analysis results and ground test data is obtained for motor case temperature histories throughout the motor firing and heat soak period of the spinning payload assist module (Star-48) qualification motors. In the area in which the insulation is exposed to combustion products during motor firing, the insulation erosion rate is a function of motor spinning rate. During heat soak, the slag mass is considered to be the single parameter that influences the thermal environment of a spinning rocket motor. Available data from a flight motor are analyzed and compared with the analysis results. The thermal environment for the PAM-S/ulysses flight motor is predicted. For a spinning flight motor, the analysis reveals that the insulation erosion rate and the amount of slag in the chamber of a spinning flight motor can be assessed or sensed from monitoring the temperature history on the outside surface of the motor case.
A LINEAR-TIME ALGORITHM FOR TESTING THE INSCRIBABILITY OF TRIVALENT POLYHEDRA

We present an algorithm for testing the inscribability of a trivalent polyhedron or, equivalently, testing the circumscribability of a simplicial polyhedron. Our algorithm, which runs in linear tim...
What To Do When You Can't Have It All: Toward a Theory of Sociotechnical Dependencies

It is often the case that ideal sociotechnical systems (STS) profiles cannot be implemented. Consequently, STS designers often must decide which among the many design features in an ideal STS profile to implement. This paper presents a theory for understanding the dependencies among ideal design features. With such a theory, if choices among ideal features must be made, the relative impact of choosing not to implement one ideal feature on the effectiveness of other ideal features will be better understood. Several propositions are offered based on the theory, including a proposal that not all ideal design features are needed since some can compensate for others. The theory was applied to manufacturing organizations and tested using data obtained from site visits to 86 companies. The results indicated that the theory significantly differentiated higher from lower performing manufacturing organizations. The theory has been embodied in a computational modeling software program that has been used by over 50 i...
On the existence of and mechanism for microwave-specific reaction rate enhancement

The use of microwave radiation to drive chemical reactions has become ubiquitous in almost all fields of chemistry. In all of these areas it is principally due to rapid and convenient heating resulting in significantly higher rates of reaction, with other advantages including enhanced product selectivity and control of materials properties. Although microwave heating continues to grow as an enabling technology, fundamental research into the nature of microwave heating has not grown at the same rate. In the case of chemical reactions run in homogeneous solution, particularly synthetic organic reactions, there is considerable controversy over the origins of rate enhancement, with a fundamental question being whether there exist microwave-specific effects, distinct from what can be attained under conventional convective heating, that can accelerate a reaction rate. In this Perspective, we discuss unique aspects of microwave heating of molecules in solution and discuss the origin and nature of microwave-specific effects arising from the process of “selective heating” of reactants in solution. Integral to this discussion is work from the field of dielectric relaxation spectroscopy, which provides a model for selective heating by Debye relaxation processes. The Perspective also includes a critical discussion of hypotheses of non-thermal effects (alternatively classified here as resonant processes) and an outline of specific reaction parameters for chemical systems in which microwave-specific Debye relaxation processes can result in observable reaction rate enhancement.
Data driven computing by the morphing fast Fourier transform ensemble Kalman filter in epidemic spread simulations

The FFT EnKF data assimilation method is proposed and applied to a stochastic cell simulation of an epidemic, based on the S-I-R spread model. The FFT EnKF combines spatial statistics and ensemble filtering methodologies into a localized and computationally inexpensive version of EnKF with a very small ensemble, and it is further combined with the morphing EnKF to assimilate changes in the position of the epidemic.
Electroweak symmetry breaking and large extra dimensions

Abstract If spacetime contains large compact extra dimensions, the fundamental mass scale of nature, Λ, may be close to the weak scale, allowing gravitational physics to significantly modify electroweak symmetry breaking. Operators of the form (1/Λ 2 )|ϕ † D μ ϕ| 2 and (1/Λ 2 )ϕ † W μν B μν ϕ , where Wμν and Bμν are the SU(2) and U(1) field strengths and ϕ is the Higgs field, remove the precision electroweak bound on the Higgs boson mass for values of Λ in a wide range: 4 TeV ≲Λ≲11 TeV . Within this framework, there is no preference between a light Higgs boson, a heavy Higgs boson, or a non-linearly realized SU(2)×U(1) symmetry beneath Λ. If there is a Higgs doublet, then operators of the form (1/Λ 2 )ϕ † ϕ(G 2 ,F 2 ) , where Gμν and Fμν are the QCD and electromagnetic field strengths, modify the production of the Higgs boson by gluon-gluon fusion, and the decay of the Higgs boson to γγ, respectively. At Run II of the Tevatron collider, a γγ signal for extra dimensions will be discovered if Λ is below 2.5 (1) TeV for a Higgs boson of mass 100 (300) GeV. Furthermore, such a signal would point to gravitational physics, rather than to new conventional gauge theories at Λ. The discovery potential of the LHC depends sensitively on whether the gravitational amplitudes interfere constructively or destructively with the standard model amplitudes, and ranges from Λ=3–10 (2–4) TeV for a light (heavy) Higgs boson.
An Anomalous Component of Galactic Emission

We present results from microwave background observations at the Owens Valley Radio Observatory. These observations, at 14.5 and 32 GHz, are designed to detect intrinsic anisotropy on scales of 7'-22'. After point-source removal, we detect significant emission with temperature spectral index ? -2 toward the north celestial pole (NCP). Comparison of our data with the IRAS 100 ?m map of the same fields reveals a strong correlation between this emission and the infrared dust emission. From the lack of detectable H? emission, we conclude that the signals are consistent either with flat-spectrum synchrotron radiation or with free-free emission from Te 106 K gas, probably associated with a large H I feature known as the NCP Loop. Assuming ? = -2.2, our data indicate a conversion Tf/I100?m = 7.5 ? 10-2?$−2.2{r GHz}$ --> K (MJy sr-1)-1. The detection of such a component suggests that we should be cautious in any assumptions made regarding foregrounds when designing experiments to map the microwave background radiation.
Jupiter Thermospheric General Circulation Model (JTGCM): Global structure and dynamics driven by auroral and Joule heating

(including auroral/Joule heating processes). The resulting JTGCM has been fully spun-up and integrated for � 40 Jupiter rotations. Results from three JTGCM cases incorporating moderate auroral heating, ion drag, and moderate to strong Joule heating processes are presented. The neutral horizontal winds at ionospheric heights vary from 0.5 km/s to 1.2 km/s, atomic hydrogen is transported equatorward, and auroral exospheric temperatures range from � 1200–1300 K to above 3000 K, depending on the magnitude of Joule heating. The equatorial temperature profiles from the JTGCM are compared with the measured temperature structure from the Galileo ASI data set. The best fit to the Galileo data implies that the major energy source for maintaining the equatorial temperatures is due to dynamical heating induced by the low-latitude convergence of the high-latitude-driven thermospheric circulation. Overall, the Jupiter thermosphere/ionosphere system is highly variable and is shown to be strongly dependent on magnetospheric coupling which regulates Joule heating.
The design and simulated performance of a coated nano-particle laser

The optical properties of a concentric nanometer-sized spherical shell comprised of an (active) 3-level gain medium core and a surrounding plasmonic metal shell are investigated. Current research in optical metamaterials has demonstrated that including lossless plasmonic materials to achieve a negative permittivity in a nano-sized coated spherical particle can lead to novel optical properties such as resonant scattering as well as transparency or invisibility. However, in practice, plasmonic materials have high losses at optical frequencies. It is observed that with the introduction of active materials, the intrinsic absorption in the plasmonic shell can be overcome and new optical properties can be observed in the scattering and absorption cross-sections of these coated nano-sized spherical shell particles. In addition, a “super” resonance is observed with a magnitude that is 103 greater than that for a tuned, resonant passive nano-sized coated spherical shell. This observation suggests the possibility of realizing a highly sub-wavelength laser with dimensions more than an order of magnitude below the traditional half-wavelength cavity length criteria. The operating characteristics of this coated nano-particle (CNP) laser are obtained numerically for a variety of configurations.
Thermal and stress analysis of semiconductor wafers in a rapid thermal processing oven

Results are presented from studies of heat transfer in a rapid thermal processing (RTP)-type oven used for several semiconductor wafer processes. These processes include: (1) rapid thermal annealing; (2) thermal gradient zone melting; and (3) lateral epitaxial growth over oxide. The heat transfer studies include the measurement of convective heat transfer in a similar apparatus, and the development of a numerical model that incorporates radiative and convective heat transfer. Thermal stresses that are induced in silicon wafers are calculated and compared to the yield stress of silicon at the appropriate temperature and strain rate. Some methods for improving the temperature uniformity and reducing thermal stresses in the wafers are discussed. >
SQUID technology applied to the study of electrochemical corrosion

Both the temporal and spatial dependences of the magnetic fields of electrochemical corrosion reactions have been investigated. A comparatively simple metal-electrolyte system, Zn in HCl, was chosen for concentrated study. Design of this corrosion cell, as well as its rationale, are described. The spectral density of the magnetic field generated by corrosion reactions has an inverse dependence on frequency. The overall noise level increases with increasing corrosion rate. These preliminary results confirm the great potential of SQUID magnetometry for the study of electrochemical corrosion phenomena.
Fair Value Opinion Shopping

ABSTRACT: This study reports the results of an experiment designed to provide empirical evidence related to fair value opinion shopping. The experiment provides initial evidence that managers are likely to shop for fair value opinions from external valuation professionals in the absence of a requirement to disclose that behavior to the board or auditor. Disclosure becomes a meaningful deterrent when the beneficiary of opinion shopping is perceived to be the manager. However, disclosure is an ineffective deterrent when the beneficiary is perceived to be shareholders.
Africa's education enigma? The Nigerian story

Abstract In the last two decades, the social and economic benefits of formal education in Sub-Saharan Africa have been debated. Anecdotal evidence points to low returns to education in Africa. Unfortunately, there is limited econometric evidence to support these claims at the micro level. In this study, I focus on Nigeria, a country that holds 1/5 of Africa's population. I use instruments based on the exogenous timing of the implementation and withdrawal of free primary education across regions in this country to consistently estimate the returns to education in the late 1990s. The results show the average returns to education are particularly low in the 90s, in contrast to conventional wisdom for developing countries (2.8% for every extra year of schooling between 1997 and 1999). Surprisingly, I find no significant differences between OLS and IV estimates of returns to education when necessary controls are included in the wage equation. The low returns to education results shed new light on both the changes in demand for education in Nigeria and the increased emigration rates from African countries that characterized the 90s.
ONTOLOGY BASED PARTIAL BUILDING INFORMATION MODEL EXTRACTION

AbstractThe current application of building information modeling (BIM) in the construction industry is generally focused on using the complete building information model during the life cycle of the project. With more information being added to the model, the size of the model file and the difficulty to manipulate the model increase. However, different use scenarios may only require access to certain specific information stored in the model. In contrast with the ample research of ontology applications in construction knowledge management, research of ontology in construction modeling has been limited. Hence, the purpose of this study is to use ontology in the extraction of a partial building information model from the original complete model. The building information models covered in this study are in the Industry Foundation Classes (IFC) format, which is a widely supported open BIM standard. An ontology TBox is developed according to the existing IFC schema specifications. For each specific IFC model, a...
A randomized comparison of the Laryngeal Mask Airway Supreme™ and Laryngeal Mask Airway Unique™ in infants and children: does cuff pressure influence leak pressure?

Summary Background The cuff pressure for optimal airway sealing with first-generation laryngeal mask airway has been shown to be 40 cm H2O in children. Currently, there are no data regarding the ideal intracuff pressure for the laryngeal mask airway Supreme (Supreme) in children. Objectives To compare the clinical performance of the laryngeal mask airway supreme with the laryngeal mask airway unique in infants and children. Materials and methods One hundred eighty children were assigned to receive either a Supreme or a laryngeal mask airway-U. We hypothesized higher airway leak pressure with the Supreme at both 40 cm H2O and 60 cm H2O, when compared with the laryngeal mask airway-U. Ease and time of insertion, insertion attempts, fiber optic examination, quality of airway, efficacy of mechanical ventilation, success of gastric tube placement (Supreme), incidence of gastric insufflation, and complications were also assessed. Results Airway leak pressure at an intracuff pressure of 60 cm H2O for the Supreme was 17.4 (5.2) vs laryngeal mask airway-U at 18.4 (6.6) cm H2O and did not differ when compared to an intracuff pressure of 40 cm H2O for both devices; Supreme at 17.2 (5) vs laryngeal mask airway-U at 17.7 (6) cm H2O. The laryngeal mask airway-U was associated with higher first-attempt success rates. The Supreme was associated with less gastric insufflation than the laryngeal mask airway-U. Conclusions Intracuff pressures of 40 cm H2O may be sufficient for the Supreme in children, and there may be no added benefit of an intracuff pressure of 60 cm H2O, as leak pressures were similar. The Supreme may be preferred over the laryngeal mask airway-U for its lower rates of gastric insufflation and provision for gastric access when mechanical ventilation is utilized.
Robust Design of RF-MEMS Cantilever Switches Using Contact Physics Modeling

This paper presents the robust design optimization of an RF-MEMS direct contact cantilever switch for minimum actuation voltage and opening time, and maximum power handling capability. The design variables are the length and thickness of the entire cantilever, the widths of the sections of the cantilever, and the dimple size. The actuation voltage is obtained using a 3-D structural-electrostatic finite-element method (FEM) model, and the opening time is obtained using the same FEM model and the experimental model of adhesion at the contact surfaces developed in our previous work. The model accounts for an unpredictable variance in the contact resistance resulting from the micromachining process for the estimation of the power handling. This is achieved by taking the ratio of the root mean square power of the RF current (ldquosignalrdquo) passing through the switch to the contact temperature (ldquonoiserdquo) resulting from the possible range of the contact resistance. The resulting robust optimization problem is solved using a Strength Pareto Evolutionary Algorithm, to obtain design alternatives exhibiting different tradeoffs among the three objectives. The results show that there exists substantial room for improved designs of RF-MEMS direct-contact switches. It also provides a better understanding of the key factors contributing to the performances of RF-MEMS switches. Most importantly, it provides guidance for further improvements of RF-MEMS switches that exploit complex multiphysics phenomena.
Analysis of Starting Circuits for a Class of Hard Oscillators: Two-Transistor Saturable-Core Parallel Inverters

One of the important practical considerations in using static dc to square-wave inverters such as the circuit shown in Fig. 1 is the reliable starting of oscillations. It is generally known that inverters of this type are not self-starting under relatively heavy load conditions. Starting under load generally is achieved through an externally added starting circuit. A variety of starting circuits have been reported from time to time in the technical literature, e.g., Ref. 1, 2 and 3. Such circuits constitute an important ingredient in many of today's state-of-the-art power processing systems. The present paper analyzes various starting circuits from the point of view of nonlinear circuit theory. The results of this analysis provide guidance in the design and selection of starting circuits and lead to a better understanding of the rather large class of inverters (4) which have circuit configurations similar to that shown in Fig. 1.
Pacific Decadal Variability in the View of Linear Equatorial Wave Theory

It has recently been proposed, within the framework of the linear shallow-water equations, that tropical Pacific decadal variability (PDV) can be accounted for by basin modes with eigenperiods of 10 to 20 yr, amplifying a midlatitude wind forcing with an essentially white spectrum. Here the authors use a different formalism of linear equatorial wave theory. The Green’s function is computed for the wind-forced response of a linear equatorial shallow-water ocean and uses the earlier results of Cane and Moore to obtain a compact, closed form expression for the motion of the equatorial thermocline, which applies to all frequencies lower than seasonal. This expression is new and allows a systematic comparison of the effect of low- and high-latitude winds on the equatorial thermocline. At very low frequencies (decadal time scales), the planetary geostrophic solution used by Cessi and Louazel is recovered, as well as the equatorial wave solution of Liu, and a formal explanation for this convergence is given. Nonetheless, this more general solution leads one to a different interpretation of the results. In contrast to the aforementioned studies, the authors find that the equatorial thermocline is inherently more sensitive to local than to remote wind forcing and that planetary Rossby modes only weakly alter the spectral characteristics of the response. Tropical winds are able to generate a strong equatorial response with periods of 10 to 20 yr, while midlatitude winds can only do so for periods longer than about 50 yr. The results suggest that ocean basin modes are an unlikely explanation of decadal fluctuations in tropical Pacific sea surface temperature.
A STABLE, ACCURATE METHODOLOGY FOR HIGH MACH NUMBER, STRONG MAGNETIC FIELD MHD TURBULENCE WITH ADAPTIVE MESH REFINEMENT: RESOLUTION AND REFINEMENT STUDIES

Performing a stable, long-duration simulation of driven MHD turbulence with a high thermal Mach number and a strong initial magnetic field is a challenge to high-order Godunov ideal MHD schemes because of the difficulty in guaranteeing positivity of the density and pressure. We have implemented a robust combination of reconstruction schemes, Riemann solvers, limiters, and constrained transport electromotive force averaging schemes that can meet this challenge, and using this strategy, we have developed a new adaptive mesh refinement (AMR) MHD module of the ORION2 code. We investigate the effects of AMR on several statistical properties of a turbulent ideal MHD system with a thermal Mach number of 10 and a plasma ?0 of 0.1 as initial conditions; our code is shown to be stable for simulations with higher Mach numbers () and smaller plasma beta (?0 = 0.0067) as well. Our results show that the quality of the turbulence simulation is generally related to the volume-averaged refinement. Our AMR simulations show that the turbulent dissipation coefficient for supersonic MHD turbulence is about 0.5, in agreement with unigrid simulations.
Electronic Thermal Expansion and the Mechanism of Coherent Acoustic Phonons Generation in Metals

We have investigated the thermal expansion dynamics of metal film using femtosecond electron diffraction. We show that the electronic thermal expansion from the transient heating of conduction electrons contributes significantly in driving coherent acoustic phonons.
A New Actuation Approach for Haptic Interface Design

Traditional haptic interfaces available today use motors to generate forces, while a more recent class of devices uses passive elements to constrain movement. This paper presents a new hybrid actuation approach that combines the use of brakes, springs and motors. The proposed actuation design is potentially safer and more energy efficient than haptic devices that only rely on motors for actuation, and also overcomes many of the rendering limitations displayed by existing passive haptic displays. Applications of this new technology range from devices where safety and reliability are of prime concerns (e.g. large force-feedback interfaces) to devices which can only be powered by limited energy sources such as small batteries (e.g. portable haptic interfaces).
A computer program for nuclear scattering at intermediate and high energies

Abstract A computer program is presented which calculates the elastic and inelastic scattering in intermediate and high energy nuclear collisions. A coupled-channels method is used for Coulomb and nuclear excitations of E1, E2, E3, M1, and M2 multipolarities, respectively. The program applies to an arbitrary nucleus, specified by the spins and energies of the levels and by reduced matrix elements. For given bombarding conditions, the angular distribution of elastic and inelastic scattered particles and angular distributions of gamma-rays from the excited nucleus are computed.
Efficient algorithms for block-cyclic array redistribution between processor sets

Run-time array redistribution is necessary to enhance the performance of parallel programs on distributed memory supercomputers. In this paper, we present an efficient algorithm for array redistribution from cyclic(x) on P processors to cyclic(Kx) on Q processors. The algorithm reduces the overall time for communication by considering the data transfer, communication schedule, and index computation costs. The proposed algorithm is based on a generalized circulant matrix formalism. Our algorithm generates a schedule that minimizes the number of communication steps and eliminates node contention in each communication step. The network bandwidth is fully utilized by ensuring that equal-sized messages are transferred in each communication step. Furthermore, the time to compute the schedule and the index sets is significantly smaller. It takes O(max(P, Q)) time and is less than 1 percent of the data transfer time. In comparison, the schedule computation time using the state-of-the-art scheme (which is based on the bipartite matching scheme) is 10 to 50 percent of the data transfer time for similar problem sizes. Therefore, our proposed algorithm is suitable for run-time array redistribution. To evaluate the performance of our scheme, we have implemented the algorithm using C and MPI on an IBM SP2. Results show that our algorithm performs better than the previous algorithms with respect to the total redistribution time, which includes the time for data transfer, schedule, and index computation.
Fingerprinting molecules based on direct measurement of absorption spectrum by frequency-tuning monochromatic THz source

By measuring the absorption spectra of three families of the common chemicals in the vapor phase, we have demonstrated that THz absorption spectroscopy could be eventually used to fingerprint molecules.
History, Advances, and Challenges in Liquid Flow and Flow Boiling Heat Transfer in Microchannels: A Critical Review

As the scale of devices becomes small, thermal control and heat dissipation from these devices can be effectively accomplished through the implementation of microchannel passages. The small passages provide a high surface area to volume ratio that enables higher heat transfer rates. High performance microchannel heat exchangers are also attractive in applications where space and/or weight constraints dictate the size of a heat exchanger or where performance enhancement is desired. This survey article provides a historical perspective of the progress made in understanding the underlying mechanisms in single-phase liquid flow and two-phase flow boiling processes and their use in high heat flux removal applications. Future research directions for (i) further enhancing the single-phase heat transfer performance and (ii) enabling practical implementation of flow boiling in microchannel heat exchangers are outlined.
Temperature dependent efficiency and modulation characteristics of Al-free 980-nm laser diodes

Temperature dependent efficiency and modulation characteristics of strained quantum-well (QW) InGaAs-InGaAsP-InGaP 980-nm laser diodes of various designs are analyzed using self consistent carrier transport analysis including stimulated emission. The decrease of the differential efficiency of 980-nm laser diodes with temperature is found to be caused by an increased modal loss attributed to the free carrier (electron and hole) absorption. The obtained results agree well with experimentally observed increase of internal loss at higher temperatures. Modulation characteristics are determined mainly by drift-diffusion in separate confinement region along with processes of carrier capture and escape in QWs. At high temperatures modulation bandwidth is reduced because of the decrease in differential gain. Graded index separate confinement heterostructure and multi-QW lasers show superior efficiency and modulation behavior at high temperatures. >
Applying an Implementation Science Framework for Adoption of a Comprehensive Program for High School Students With Autism Spectrum Disorder

Post-school outcomes for adolescents and young adults with autism spectrum disorder (ASD) are exceedingly poor. The convergence of adolescence as a development period, the expression of ASD during adolescence, and the complicated logistic nature of high schools create a perfect storm of complexity that may pose challenges and establish barriers to providing an effective secondary education program. Given this complexity, addressing learning needs for adolescents with ASD and improving post-school outcomes requires a comprehensive approach. In this article, the authors describe a set of implementation science principles and practices that could be employed in supporting the adoption and implementation of a comprehensive program for high school students with ASD. The program developed by the Center on Secondary Education for Students With Autism Spectrum Disorder (CSESA) serves as a case example of how such principles and practices may be employed in program planning and implementation.
Historical Analogies, Slippery Slopes, and the Question of Euthanasia

The German Nazi regime has become a standard model for unspeakable things that one should reject. Contemporary people will characterize political opponents, benighted policies, and other undesirable things as “fascist” or “Nazi.” In ethics, and medical ethics in particular, this analogy arises regularly. Therefore, it is not surprising that German people are particularly sensitive about their history. For example, the German high court regularly refers to the Nazi era in its reluctance to accept lethal social activities. This sensitivity surfaced again in 1988, when influential applied ethicist Peter Singer accepted a German invitation to speak to a Symposium on “Bioengineering, Ethics, and Mental Disability.” Singer had also agreed to deliver a separate lecture on the topic “Do severely disabled newborn infants have a right to life?”
Energy Landscape and Transition State of Protein-Protein Association

Formation of a stereospecific protein complex is favored by specific interactions between two proteins but dis- favored by the loss of translational and rotational freedom. Echoing the protein folding process, we have previously proposed a transition state for protein-protein association. Here we clarify the specification of the transition state by working with two types of toy models for protein association. A ''hemisphere'' model consists of two matching hemispheres as associating proteins, and a ''crater'' model consists of a spherical protein with a crater to which another spherical protein fits snugly. Short-range pairwise interactions between sites across the interface hold together the bound complex. Small relative translation and rotation between the subunits quickly destroy the interactions, leading to a sharp transition between the bound state with numerous short-range interactions but restricted translation and rotational freedom and the unbound state with, at most, a small number of interactions but expanded configurational freedom. This transition sets the outer boundary of the bound state as well as the transition state for association. The energy landscape is funnel-like, with the deep well of the bound state surrounded by a broad shallow basin. Calculations with the toy models suggest that mutational change in the interaction energy in the x-ray structure of a protein- protein complex, commonly used to approximate the effect on the association constant, overestimates the effect of mutation by 10-20%. With an eye toward specifying the transition states of actual protein complexes, we find that the total number of contacts between the subunits serves as a good surrogate of the interaction energy. This formalism of protein-protein asso- ciation is applied to the barnase-barstar complex, reproducing the experimental results for the association rate over a wide range of ionic strength.
Organizational Restructuring and its Consequences: Rhetorical and Structural

In this review, we examine the idea of organizational restructuring as a conceptual tool and how it has been used to alter societal definitions and interpretations of employment. Although use of the term restructuring is relatively recent, the broad issue of changing employment conditions with which it is concerned has a long history, going back to the industrial revolution. Our main focus is a consideration of the causes and consequences of restructuring, in its more recent rhetorical and structural versions. In their pursuit of greater efficiencies, organizations adapt to the demands of increasingly global markets, and these adaptations are crucial components of what is popularly referred to as the new economy. Such developments are applauded in most economic theory, but sociologists examine both sides of their social impact, including the adverse effects and implications of such externalities as the social disruptions caused by downsizing and other organizational and corporate changes. These studies pr...
NANO-SCALE MATERIALS DEVELOPMENT FOR FUTURE MAGNETIC APPLICATIONS

Developments in the field of magnetic materials which show promise for future applications are reviewed. In particular recent work in nanocrystalline materials is reviewed, with either soft or hard behavior as well as advances in the magnetic materials used for magnetic recording. The role of microstructure on the extrinsic magnetic properties of the materials is stressed and it is emphasized how careful control of the microstructure has played an important role in their improvement. Important microstructural features such as grain size, grain shape and crystallographic texture all are major contributors to the properties of the materials. In addition, the critical role that new instrumentation has played in the better understanding of the nano-phase magnetic materials is demonstrated.