cssi/SciSciGPT-SciSciNet huggingface dataset:
Consociationalism and Power Sharing in Africa: Rwanda, Burundi, and the Democratic Republic of the Congo

Although there are obvious merits to the consociational argument, including the need to recognize the claims of minorities through power-sharing arrangements, translating theory into practice has generally failed in much of Africa. The reasons for this are many and are by no means reducible to single-factor explanations. Looking at the recent experiments in power sharing in former Belgian Africa, this article offers a comparative assessment of the radically different trajectories followed by Rwanda, Burundi, and the Democratic Republic of the Congo (DRC) in their efforts to regulate conflict through consociational formulas. Although Rwanda stands as a textbook example of failed power sharing, and the DRC as a less than successful experiment, Burundi, which comes nearest to institutionalizing the Lijphart model, offers grounds for cautious optimism about the merits of a consociational polity. On the strength of the evidence from Burundi, one might conceivably argue that the key to success lies in the extent to which the technicalities of power sharing tend to approximate the conditions spelled out by Lijphart, notably group autonomy, proportionality, and the minority veto. Closer scrutiny of the cases at hand suggests a somewhat different conclusion. Perhaps even more importantly than the mechanics of power sharing, the socio-political context is what spells the difference between success and failure. SINCE ITS FORMULATION BY AREND LIJPHART IN THE 1970s, few theories have had a more enduring impact on the thinking of analysts and practitioners of democratic governance than the consociational model.' Its underlying Rend Lemarchand (renelemar@aol.com) is professor emeritus of Political Science at the University of Florida. He has written extensively on the Great Lakes region of Central Africa. This article is a much revised version of a paper presented in February 2006 at a conference on 'Managing ethno-political conflicts in Africa' jointly organized by the Solomon Ash Center for the Study of Ethno-Political Conflict at the University of Pennsylvania and the Centre for Peace and Conflict Studies of the University of Ibadan, Nigeria. The author wishes to thank the participants in the conference, notably, Brendan O'Leary, and the joint editors of this journal for their searching comments when the article was still in draft form. 1. Arendt Lijphart, Democracy in Plural Societies: A comparative exploration (Yale University Press, New Haven, CT, 1977), and for a more succinct formulation, 'The power-sharing approach', in Joseph V. Montville (ed.), Conflict and Peace-Making in Multiethnic Societies (D.C. Heath, Lexington, KY, 1990), pp. 491-509.
Intention awareness: improving upon situation awareness in human-centric environments

As the gap between human and machine shrinks, it becomes increasingly important to develop computer systems that incorporate or enhance existing Situation Awareness. However, these tend to focus on raw quantitative parameters, such as position and speed of objects. When these situations are governed by human actors, such parameters leave significant margins of uncertainty. In this paper, we discuss the potential of applying the characteristics intrinsic to the human actors that comprise a given situation to Situation Awareness, and the capacity that these concepts have to improve situation-aware systems. We argue that intention-aware based systems offer an advantage over situation-aware based systems in that they reduce the informational burden on humans without limiting effectiveness. We argue that computational analysis and tracking of semantic and affective information associated with human actors' intentions are an effective way to minimize miscommunication and uncertainty, particularly in time-sensitive and information-saturated situations.
A Capstone Design Experience in Architectural Engineering Technology

At the University of Hartford, we have developed a "Capstone Design Experience" in an effort to improve our Architectural Engineering Technology curriculum. By increasing the awareness of the interrelationships between different areas of study, we are attempting to strike a new balance. We have integrated the following into a single year-long design project: research, programming, planning, history and theory, design, model making, drawing, CAD (computer aided design), structures, environmental systems, presentations and writing. Our capstone program provides opportunities for exploration, questioning, testing, and criticism. It requires the students to use experience and knowledge gained in other courses and forces them to play an active role in their own learning. It demands personal accountability for decisions, and commitment to ideas and proposals that are scrutinized publicly. We believe that we have developed a model that other disciplines on campus could well profit from observing.
Solving sparse linear constraints

Linear arithmetic decision procedures form an important part of theorem provers for program verification. In most verification benchmarks, the linear arithmetic constraints are dominated by simple difference constraints of the form x ≤y + c. Sparse linear arithmetic (SLA) denotes a set of linear arithmetic constraints with a very few non-difference constraints. In this paper, we propose an efficient decision procedure for SLA constraints, by combining a solver for difference constraints with a solver for general linear constraints. For SLA constraints, the space and time complexity of the resulting algorithm is dominated solely by the complexity for solving the difference constraints. The decision procedure generates models for satisfiable formulas. We show how this combination can be extended to generate implied equalities. We instantiate this framework with an equality generating Simplex as the linear arithmetic solver, and present preliminary experimental evaluation of our implementation on a set of linear arithmetic benchmarks.
Crystal structure, electronic structure, and thermoelectric properties of AuTlSb: A new pyrite superstructure

Abstract The ternary compound AuTlSb adopts a new structure type in the orthorhombic space group Pna 2 1 with lattice constants a = 6.5507(8) A, b = 14.2871(18) A, c = 6.5254(9) A. The structure contains Au atoms octahedrally coordinated to Sb Sb and Tl Tl dimers, and can be viewed as an ordered superstructure of AuSb 2 (pyrite). In addition to the synthesis and crystal structure of AuTlSb, we report extended Huckel band structure calculations and bonding analysis, as well as electrical resistivity and thermopower measurements between 80 K and 300 K. For comparison, we include the results from extended Huckel calculations on the parent structure AuSb 2 . The band structure calculations predict AuTlSb to be metallic, which is in agreement with the transport properties measurements.
Critical issues of wafer level chip scale package (WLCSP) with emphasis on cost analysis and solder joint reliability

Some of the critical issues of wafer level chip scale package (WLCSP) are mentioned and discussed in this investigation. Emphasis is placed on the cost analysis of WLCSP through the, important parameters such as wafer-level redistribution, wafer-bumping, and wafer-level underfilling. Useful and simple equations in terms of these parameters are also provided. Furthermore, the effects of microvia build-up layer on the solder joint reliability of WLCSP on printed circuit board (PCB) through the creep responses such as the deformation, hysteresis loops, and stress and strain are presented. Only solder-bumped with pad-redistribution WLCSPs are considered in this study.
Analysis of low-level code using cooperating decompilers

Analysis or verification of low-level code is useful for minimizing the disconnect between what is verified and what is actually executed and is necessary when source code is unavailable or is, say, intermingled with inline assembly. We present a modular framework for building pipelines of cooperating decompilers that gradually lift the level of the language to something appropriate for source-level tools. Each decompilation stage contains an abstract interpreter that encapsulates its findings about the program by translating the program into a higher-level intermediate language. We provide evidence for the modularity of this framework through the implementation of multiple decompilation pipelines for both x86 and MIPS assembly produced by gcc, gcj, and coolc (a compiler for a pedagogical Java-like language) that share several low-level components. Finally, we discuss our experimental results that apply the BLAST model checker for C and the Cqual analyzer to decompiled assembly.
Tools and best practices for data processing in allelic expression analysis

Allelic expression analysis has become important for integrating genome and transcriptome data to characterize various biological phenomena such as cis-regulatory variation and nonsense-mediated decay. We analyze the properties of allelic expression read count data and technical sources of error, such as low-quality or double-counted RNA-seq reads, genotyping errors, allelic mapping bias, and technical covariates due to sample preparation and sequencing, and variation in total read depth. We provide guidelines for correcting such errors, show that our quality control measures improve the detection of relevant allelic expression, and introduce tools for the high-throughput production of allelic expression data from RNA-sequencing data.
Management of Hyperuricemia with Rasburicase Review

Tumor lysis syndrome (TLS) is a serious complication in patients with hematological malignancies. Massive lysis of tumor cells can lead to hyperuricemia, hyperkalemia, hyperphosphatemia and hypocalcaemia. These metabolic disturbances may result in renal failure, because of precipitation of uric acid crystals and calcium phosphate salts in the kidney. The standard prophylaxis or treatment of hyperuricemia consists of decreasing uric acid production with allopurinol and facilitating its excretion by urinary alkalinization and hyperhydration. By inhibiting the enzyme xanthine oxidase, allopurinol blocks the conversion of hypoxanthine and xanthine into uric acid. An alternative treatment is urate oxidase which oxidates uric acid into allantoin. Allantoin is 5-10 times more soluble than uric acid and is therefore excreted easily. In several clinical trials rasburicase, the recombinant form of urate oxidase, has shown to be very effective in preventing and treating hyperuricemia. Rasburicase, in contrast with the non-recombinant form of urate oxidase uricozyme, is associated with a low incidence of hypersensitivity reactions. In addition to the demonstrated clinical benefit, rasburicase also proved to be a cost-effective option in the management of hyperuricemia.
ASYMPTOTIC EVOLUTION OF ACYCLIC RANDOM MAPPINGS

An acyclic mapping from an $n$ element set into itself is a mapping $\varphi$ such that if $\varphi^k(x) = x$ for some $k$ and $x$, then $\varphi(x) = x$. Equivalently, $\varphi^\ell = \varphi^{\ell+1} = \ldots$ for $\ell$ sufficiently large. We investigate the behavior as $n \rightarrow \infty$ of a sequence of a Markov chain on the collection of such mappings. At each step of the chain, a point in the $n$ element set is chosen uniformly at random and the current mapping is modified by replacing the current image of that point by a new one chosen independently and uniformly at random, conditional on the resulting mapping being again acyclic. We can represent an acyclic mapping as a directed graph (such a graph will be a collection of rooted trees) and think of these directed graphs as metric spaces with some extra structure. Informal calculations indicate that the metric space valued process associated with the Markov chain should, after an appropriate time and ``space'' rescaling, converge as $n \rightarrow \infty$ to a real tree ($R$-tree) valued Markov process that is reversible with respect to a measure induced naturally by the standard reflected Brownian bridge. Although we don't prove such a limit theorem, we use Dirichlet form methods to construct a Markov process that is Hunt with respect to a suitable Gromov-Hausdorff-like metric and evolves according to the dynamics suggested by the heuristic arguments. This process is similar to one that appears in earlier work by Evans and Winter as a similarly informal limit of a Markov chain related to the subtree prune and regraft tree (SPR) rearrangements from phylogenetics.
Testing for stationarity-ergodicity and for comovements between nonlinear discrete time Markov processes

In this paper we introduce a class of nonlinear data generating processes (DGPs) that are "rst order Markov and can be represented as the sum of a linear plus a bounded nonlinear component. We use the concepts of geometric ergodicity and of linear stochastic comovement, which correspond to the linear concepts of integratedness and cointegratedness, to characterize the DGPs. We show that the stationarity test due to Kwiatowski et al. (1992, Journal of Econometrics, 54, 159}178) and the cointegration test of Shin (1994, Econometric Theory, 10, 91}115) are applicable in the current context, although the Shin test has a di!erent limiting distribution. We also propose a consistent test which has a null of linear cointegration (comovement), and an alternative of n C22
Universal multiple description scalar quantization: analysis and design

This paper introduces a new high-rate analysis of the multiple description scalar quantizer (MDSQ) with balanced descriptions. The analysis provides insight into the structure of the MDSQ, suggesting the nonoptimality of uniform central quantizer cell lengths, as well as a method to approximate optimal cell lengths. For both level-constrained and entropy-constrained MDSQ, new upper bounds on the granular distortion for sources with smooth probability density functions (pdfs) are derived under the mean-squared error measure, which are 0.4 dB lower than previous results. Based on the insights, a universal multiple description scalar quantizer (UMDSQ) is proposed which, at high rate, can achieve nearly the same performance as the fully optimized entropy-constrained MDSQ (ECMDSQ), without requiring extensive training. The proposed UMDSQ has only two control parameters, and a continuum of tradeoff points between the central and side distortions can be achieved as the two parameters are varied.
Privatization : trends and recent developments

This paper takes stock of recent privatization trends, examines the extent to which government ownership is still prevalent in developing countries, and summarizes emerging issues for state enterprise reform going forward. Between 1990 and 2003, 120 developing countries carried out nearly 8,000 privatization transactions and raised $410 billion in privatization revenues. Privatization activity peaked in 1997 and dropped off in the late 1990s and, while still at overall low levels, is slowly creeping back. While there are a large number of studies assessing the impact of privatization on enterprise performance and overall welfare, there are no systematic data on the extent to which privatization has changed the role of state enterprises in the economy. Anecdotal evidence suggests that the state's role has been substantially reduced in Eastern and Central Europe and in certain countries in Latin America. But available evidence also suggests that, despite a long track record of privatization, government ownership in state enterprises is still widely prevalent in some regions and countries, and in certain sectors in virtually all regions. The paper shows that the costs of not reforming state enterprises are high and that continued efforts need to be made to improve their performance by improving privatization policies and institutions; adopting more of a case-by-case approach for complex sectors and countries; and exposing state enterprises to market discipline through new private entry and exit of unviable firms and improvements in their corporate governance.
Hydrothermal Synthesis of Bismuth Titanate Powders

Bismuth titanate was synthesized under hydrothermal conditions from an amorphous bismuth–titanium precursor gel. The gel was formed by mixing a bismuth acetate complex with titanium butoxide and then adding the solution dropwise into 6M NaOH. The resulting gel suspension was reacted under hydrothermal conditions at temperatures ranging from 160° to 200°C to form crystalline bismuth titanate. The gel crystallization kinetics increased with temperature, which resulted in 100% crystalline bismuth titanate in 5 h at 200°C. Wavelength-dispersive spectroscopy data indicated that sodium was incorporated into bismuth titanate during processing, and X-ray diffractometry suggested that the powder was composed of the Bi5Ti4O15 phase. Transmission electron microscopy micrographs showed that the gel particles decomposed to 100–200 nm crystalline bismuth titanate particles during hydrothermal processing.
Addressing the Challenges of Plasma-Surface Interactions in NSTX-U

The importance of conditioning plasma-facing components (PFCs) has long been recognized as a critical element in obtaining high-performance plasmas in magnetic confinement devices. Lithium coatings, for example, have been used for decades for conditioning PFCs. Since the initial studies on the Tokamak Fusion Test Reactor (TFTR), experiments on devices with different aspect ratios and magnetic geometries like the National Spherical Torus Experiment (NSTX) continue to show the relationship between the lithium PFCs and good confinement and stability. While such results are promising, their empirical nature do not reflect the detailed relationship between the PFCs and the dynamic conditions that occur in the tokamak environment. A first step developing an understanding such complexity will be taken in the upgrade to NSTX, or the National Spherical Torus Experiment-Upgrade (NSTX-U) that is nearing completion. New measurement capabilities include the materials analysis and particle probe for in situ surface analysis of samples exposed to tokamak plasmas. The onion-skin modeling for edge analysis (OEDGE) suite of codes, for example, will be used to model the underlying mechanisms for such material migration in NSTX-U. This will lead to a better understanding of how plasma-facing surfaces evolve during a shot, and how the composition of the plasma-facing surface influences the discharge performance we observe. This paper will provide an overview of these capabilities, and highlight their importance for NSTX-U plans to transition from carbon to high- ${Z}$ PFCs.
Hitchhiker’s guide to inflation in Libya

This paper presents an empirical investigation of inflation dynamics in Libya over the period 1964–2012, using cointegration and error correction models. While inflation inertia is found to be a key determinant of consumer price inflation, the results indicate that government spending, money supply growth, global inflation, and exchange rate pass-through play central roles in the inflation process. These findings are broadly consistent with the experience of other countries that are natural resource dependent. We also find evidence that the imposition and subsequent removal of international sanctions on Libya had a significant impact on consumer price inflation. Collectively, our econometric estimates indicate that the deviations from an equilibrium path initiate significant adjustments in inflation dynamics, and that closer coordination between monetary and fiscal policies would improve the balance between economic growth and price stability.
Operator Valued Hardy Spaces

Introduction Preliminaries The Duality between $\mathcal H^1$ and BMO The maximal inequality The duality between $\mathcal H^p$ and $\textrm {BMO}^q, 1 < p < 2$ Reduction of BMO to dyadic BMO Interpolation Bibliography.
Real-time path planning for virtual agents in dynamic environments

We present a novel approach for real-time path planning of multiple virtual agents in complex dynamic scenes. We introduce a new data structure, Multi-agent Navigation Graph (MaNG), which is constructed from the first- and second-order Voronoi diagrams. The MaNG is used to perform route planning and proximity computations for each agent in real time. We compute the MaNG using graphics hardware and present culling techniques to accelerate the computation. We also address undersampling issues for accurate computation. Our algorithm is used for real-time multi-agent planning in pursuit-evasion and crowd simulation scenarios consisting of hundreds of moving agents, each with a distinct goal.
Interest Coalitions and Multilateral Aid Allocation in the European Union

This paper analyzes multilateral aid allocation in the European Union (EU). We argue that EU members can influence the aid allocation process toward their national interests if they form powerful coalitions that bias the European Commission's development policies. When EU members' preferences over aid allocation are heterogeneous, the Commission can implement multilateral aid according to its programmatic goals. Greater homogeneity of EU members' goals, however, increases the likelihood that members can form powerful interest coalitions and induce the Commission to allocate aid according to their own national interests. The empirical analysis provides robust support for our theoretical argument, and the findings generally indicate that interest coalitions play an important role in multilateral aid allocation.
Decentralized control of a class of large-scale systems with symmetrically interconnected subsystems

This paper discusses a class of large-scale systems composed of several similar subsystems interconnected with an external system in a symmetrical fashion. A method of determining the set of fixed modes of such a system with respect to decentralized (or partly decentralized) control is presented in terms of the modified subsystems. The completeness of these systems is studied, and a simple condition for such a system to be complete is derived.
Gap solitons in almost periodic one-dimensional structures

We consider almost periodic stationary nonlinear Schrodinger equations in dimension 1. Under certain assumptions we prove the existence of nontrivial finite energy solutions in the strongly indefinite case. The proof is based on a carefull analysis of the energy functional restricted to the so-called generalized Nehari manifold, and the existence and fine properties of special Palais–Smale sequences. As an application, we show that certain one dimensional almost periodic photonic crystals possess gap solitons for all prohibited frequencies.
How Teachers' Unions Affect Education Production

This study helps to explain why measured school inputs appear to have little effect on student outcomes, particularly for cohorts educated since 1960. Teachers' unionization can explain how public schools simultaneously can have more generous inputs and worse student performance. Using panel data on United States school districts, I identify the effect of teachers' unionization through differences in the timing of collective bargaining, especially timing determined by the passage of state laws that facilitate teachers' unionization. I find that teachers' unions increase school inputs but reduce productivity sufficiently to have a negative overall effect on student performance. Union effects are magnified where schools have market power.
Enantioselective Rauhut-Currier reactions promoted by protected cysteine.

We report highly enantioselective examples of the Rauhut−Currier cycloisomerization reaction (the “vinylogous Morita−Baylis−Hillman reaction”). The reaction is highly practical and is catalyzed by a commercially available derivative of the proteinogenic amino acid cysteine. Reactions are conducted in the presence of potassium tert-butoxide and a critical concentration of water in bulk acetonitrile. A mechanistic model is advanced that may account for reaction selectivity that is predicated on organizational chelation of K ion in the product-determining step in which the Cys derivative undergoes elimination.
Intensity of Food Stamp Use and Transient and Chronic Poverty: Evidence from the Panel Study of Income Dynamics

The relationship between food assistance and inter-annual family poverty dynamics is examined using data from the 1995-2003 Panel Study of Income Dynamics. We generate expenditure-based poverty measures to examine the determinants of transient and chronic poverty, with particular focus on the differential role that Food Stamp Program (FSP) participation may have on each dimension of poverty. Results indicate that transient poverty accounts for a larger share of economic hardship than chronic poverty. Both dimensions of poverty are reduced at nearly the same rate by additional months of FSP participation. In general, the determinants of chronic and transient poverty are not found to differ significantly; both aspects of poverty appear to be correlated with age of household head, human capital, minority status, rural residence and local economic conditions.
Modeling Technique to Predict Fields, Currents, and Loads for C-Mod's Advanced Outer Divertor During a Disruption With a 2.5-MA Plasma Current and 9-T Toroidal Field

Models have been built using the finite-element software COMSOL to predict fields, currents, and the resulting loads and stresses acting on the C-mod advanced outer divertor (AOD). The AOD is being designed to operate with conditions of a 2.5-MA plasma current and a toroidal field of 9 T while being held at 600 °C, and so must survive a disruption that occurs in these conditions. In addition to the loads resulting from eddy currents induced in the divertor during a disruption, the divertor will at times need to carry up to 400 kA of halo current, which crosses the toroidal field as it returns to the plasma. The loads resulting from this scenario will be very high, and we have had to develop models to predict the fields, currents, and loads as accurately as possible to ensure that the strength of the new design can withstand these loads. First, the fields and eddy currents are predicted in a COMSOL model of C-mod given two inputs. The first input is the currents for the toroidal and poloidal field coils, which come from measured data taken during a discharge. The second input is the current in the plasma, which comes from another model that solves Maxwell's equations to reconstruct the plasma as 24 current carrying filaments. The advantage of this new modeling technique is that it provides the ability to create a model based on actual measured data and to model whichever type of disruption, whether a midplane disruption or a vertical displacement event, so that the model more accurately reflects operating conditions the AOD will see. In addition to the Lorenz forces due to the induced eddy currents in the AOD, the model can also calculate the large forces due to halo currents that cross C-mod's large toroidal field. The loads due to the halo currents will be the largest loads the divertor sees. With all the loads defined, a structural model of the divertor is run to determine stresses and displacements.
Bonnesen-type inequalities for surfaces of constant curvature

A Bonnesen-type inequality is a sharp isoperimetric inequality that includes an error estimate in terms of inscribed and circumscribed regions. A kinematic technique is used to prove a Bonnesen-type inequality for the Euclidean sphere (having constant Gauss curvature @k>0) and the hyperbolic plane (having constant Gauss curvature @k 0.
On the banach-space-valued azuma inequality and small-set isoperimetry of alon-roichman graphs

We discuss the connection between the expansion of small sets in graphs, and the Schatten norms of their adjacency matrices. In conjunction with a variant of the Azuma inequality for uniformly smooth normed spaces, we deduce improved bounds on the small-set isoperimetry of Abelian Alon-Roichman random Cayley graphs.
Unethical Demand and Employee Turnover

This paper argues that consumer demand for unethical behavior such as fraud can impact employee turnover through market and psychological forces. Widespread conditions of unethical demand can improve career prospects for employees of unethical firms through higher income and stability associated with firm financial health. Similarly, unethical employees enjoy increased tenure from the financial and psychological rewards of prosocial behavior toward customers demanding corrupt or unethical behavior. We specifically examine the well-documented unethical demand for fraud in the vehicle emissions testing industry, and its impact on employee tenure. We use data from tests conducted by several thousand licensed inspectors to demonstrate that fraudulent employees and employees of fraudulent firms enjoy longer tenure. These results suggest further work to separate the multiple psychological and economic mechanisms likely driving our findings.
Linear model validation and order selection using higher order statistics

There exists several methods for fitting linear models to linear stationary nonGaussian signals using higher order statistics. The models are fitted under certain assumptions on the data and the underlying (true) model. This paper is devoted to the problem of model validation, i.e., to checking if the fitted linear model is consistent with the underlying basic assumptions. Model order selection is a by-product of the solution. We provide a fairly easy-to-apply statistical test based on the asymptotic properties of the bispectrum of the inverse filtered data. Computer simulation results are presented for both linear model validation and model order selection. The proposed model order selection approach is compared with an existing order selection method based upon rank testing via singular value decomposition. >
Spectral emissivity of carbon particle clouds in rocket exhausts.

The spectral and temperature dependence of the absorption coefficient of clouds of small carbon particles, produced by research rocket engines burning RP-1 and Oz(g), was determined between 1 and 4 ^ and between 1000° and 2600°K. The product of k\ and carbon mass fraction was determined from measurements at the exit plane of engines designed to produce uniform exit conditions. Temperature dependence was determined by expanding combustion products produced under identical combustion chamber conditions to three different area ratios. At temperatures below 1700°K, the dependence of k\ on T and A agrees reasonably well with a theoretical calculation based on the d.c. conductivity of bulk carbon and appropriate to very small particles. For T > 1700°K, the measured values of k\ behave quite differently from the calculation. A set of normalized "absolute" absorption coefficients has been obtained by matching the low-temperature data to the calculation at a molecular spectral window. Methods of predicting radiative base heat transfer from carbon emission in large engines, using these data, are briefly discussed.
Estimating the Subsonic Aerodynamic Center and Moment Components for Swept Wings

DOI: 10.2514/1.33445 An improved method is presented for estimating the subsonic location of the semispan aerodynamic center of a swept wing and the aerodynamic moment components about that aerodynamic center. The method applies to wings withconstantlineartaperandconstantquarter-chordsweep.Theresultsofacomputational fluiddynamicsstudyfor 236 wings show that the position of the semispan aerodynamic center of a wing depends primarily on aspect ratio, taperratio,andquarter-chordsweepangle.Wingaspectratiowasvariedfrom4.0to20,taperratiosfrom0.25to1.0 were investigated, quarter-chord sweep angles were varied from 0 to 50 deg, and linear geometric washout was variedfrom4:0to8:0 deg.AllwingshadairfoilsectionsfromtheNACA4-digitairfoilserieswithcambervaried from0to4%andthicknessrangingfrom6to18%.Withintherangeofparametersstudied,wingcamber,thickness, and twist were shown to have no significant effect on the position of the semispan aerodynamic center. The results of thisstudyprovideimprovedresolutionofthesemispanaerodynamiccenterandmomentcomponentsforconceptual design and analysis.
Pairing mechanism in Fe-based superconductors

I review recent works on the symmetry and the structure of the superconducting gap in Fe-based superconductors (FeSCs) and on the underlying pairing mechanism in these systems. The experimental data on superconductivity show very rich behavior, with potentially different symmetry of a superconducting state for different compositions of the same material. The variety of different pairing states raises the issue of whether the physics of FeSCs is model dependent or is universal, governed by a single underlying pairing mechanism. I argue that the physics is universal and that all pairing states obtained so far can be understood within the same universal pairing scenario and are well described by the effective low-energy model with small numbers of input parameters.
Pseudo Market Timing and the Long-Run Underperformance of IPOs

Numerous studies document long-run underperformance by firms following equity offerings. This paper shows that underperformance is very likely to be observed ex-post in an efficient market. The premise is that more firms issue equity at higher stock prices even though they cannot predict future returns. Ex-post, issuers seem to time the market because offerings cluster at market peaks. Simulations based on 1973 through 1997 data reveal that when ex-ante expected abnormal returns are zero, median ex-post underperformance for equity issuers will be significantly negative in event-time. Using calendar-time returns solves the problem.
Aging and decision making: a comparison between neurologically healthy elderly and young individuals

We report the results of experiments on economic decisions with two populations, one of healthy elderly individuals (average age 82) and one of younger students (average age 20). We examine confidence, decisions under uncertainty, differences between willingness to pay and willingness to accept and the theory of mind (strategic thinking). Our findings indicate that the older adults’ decision behavior is similar to that of young adults, contrary to the notion that economic decision making is impaired with age. Moreover, some of the demonstrated decision behaviors suggest that the elderly individuals are less biased than the younger individuals.
Frequency-Domain Oversampling for Zero-Padded OFDM in Underwater Acoustic Communications

Although time-domain oversampling of the received baseband signal is common for single-carrier transmissions, the counterpart of frequency-domain oversampling is rarely used for multicarrier transmissions. This is because frequency-domain oversampling cannot be taken advantage of, when using the commonly used low-complexity receiver that assumes orthogonal subcarriers. In this paper, we explore frequency-domain over-sampling to improve the system performance of zero-padded (ZP) orthogonal frequency division multiplexing (OFDM) transmissions over underwater acoustic channels with large Doppler spread. In these channels, intercarrier interference (ICI) has to be addressed explicitly via frequency-domain equalization, which enables inclusion of additional frequency samples at little increased complexity. We use a signal design that enables separate sparse channel estimation and data detection, reducing equalization complexity. Based on both simulation and experimental results, we observe that the receiver with frequency-domain oversampling outperforms the conventional one considerably, where the gain increases as the Doppler spread increases.
Neurology of developmental dyslexia

Developmental dyslexia was until recently considered to belong solely in the domain of educational psychology. With the advent of better theories on language and reading, and better methods for assessing the structure and function of living human brains and for determining genetic transmission, dyslexia is now poised to become a focal concern of cognitive neuroscience, neurology, and genetic research. Still unresolved are questions relating to how much a reading disability represents a normal variation or a separate pathological entity, and whether the cognitive disorder is primarily cognitive, or secondary to a disorder in early perception. Recent findings from neuroanatomy, neurophysiology, neuropsychology, and genetics research are reviewed. (This review is an updated version of a review first published in Current Opinion In Neurology and Neurosurgery 1992, 5:71-76.)
Fundamental reactions of free radicals relevant to pyrolysis reactions

Abstract Free-radical mechanisms are ubiquitous for pyrolysis of organic substrates. Background information is supplied to assist in the interpretation of such reactions by dissection into the elementary radical-forming, radical-consuming, and radical-interconverting reactions that form the building blocks of overall mechanisms. Particular attention is given to homolysis, hydrogen abstraction, β-scission–addition, and rearrangement steps, and to bond-breaking and bond-forming processes. Since the thermochemistry of such elementary reactions is dependent on the stability of the radicals involved, the major influences of structural changes on radical stability are reviewed. Kinetics of prototypical elementary reactions and their responses to structural changes are rationalized in terms of their Arrhenius parameters. The fundamental relationships between thermochemical parameters and kinetic parameters are summarized, and the use of these to estimate rate constants for cases where data is not available is demonstrated. Some kinetic consequences of the combination of elementary reactions to produce chain reactions are reviewed. Critical structural and kinetic features that determine the selectivity among product types and the response of reactions to temperature and substrate concentration are indicated.
In-Vivo and Postmortem Compressive Properties of Porcine Abdominal Organs

In order to provide realistic haptic feedback, simulators must incorporate accurate computational models of the in-vivo mechanical behavior of soft tissues. Surgical simulation technology has progressed rapidly but lacks a comprehensive database of soft tissue mechanical properties with which to incorporate. Simulators are often designed purely based on what “feels about right;” quantitative empirical data are lacking. It is important to test tissues in-vivo and apply surgically relevant ranges of force, deformation, and duration. A motorized endoscopic grasper was used to test seven porcine abdominal organs in-vivo, in-situ, and ex-corpus with cyclic and static compressive loadings. Elastic and stress relaxation characteristics were examined. Results from liver are presented here. Notable differences were found between successive squeezes and between conditions for elastic and relaxation behaviors.
Cosmological model differentiation through weak gravitational lensing

We investigate the potential of weak gravitational lensing maps to differentiate between distinct cosmological models, considering cosmic variance owing to a limited map extension and the presence of noise. We introduce a measure of the differentiation between two models under a chosen lensing statistics. That enables one to determine in which circumstances (map size and noise level), and for which lensing measures two models can be differentiated at a desired confidence level. As an application, we simulate convergence maps for three cosmological models (SCDM, OCDM, and ΛCDM), calculate several lensing analyses for them, and compute the differentiation between the models under these analyses. We use first, second, and higher order statistics, including Minkowski functionals, which provide a complete morphological characterization of the lensing maps. We examine for each lensing measure used how noise affects its description of the convergence, and how this affects its ability to differentiate between cosmological models. Our results confirm the use of weak gravitational lensing as a valuable cosmological tool.
A computational analysis of the Needham-Schroeder-(Lowe) protocol

The Needham Schroeder protocol and its repaired verdion due to Lowe are the main test cases used by symbolic methods for cryptographic protocol analysis. In this paper we proved the first computational analysis of the protocol. We start by translating Lowe's attack against the orginal protocol into the computational framework that we use in our analysis. Then we prove that the repaired protocol may not be secure. even when the encryption scheme that is used in its implementation satisfies indistinguishability under chosen-plaintext attack, This shows that symbolic security analysis is not sound for protocols that use this kind of encryption. Our main result is to prove that the Needham-schroeder-Lowe protocol is secure if it is Implemented with an encryption scheme that satisfies the stronger notion of indistinguishability under chosen-ciphertext attack.
Implementation of the Jäger contact model for discrete element simulations

In three-dimensional discrete element method (DEM) simulations, the particle motions within a granular assembly can produce bewildering sequences of movements at the contacts between particle pairs. With frictional contacts, the relationship between contact movement and force is non-linear and path-dependent, requiring an efficient means of computing the forces and storing their histories. By cleverly applying the principles of Cattaneo, Mindlin, and Deresiewicz, J”urgen Jager developed an efficient approach for computing the full three-dimensional force between identical elastic spheres that have undergone difficult movement sequences (J. Jager, New Solutions in Contact Mechanics. WIT Press: Southampton, U.K.). This paper presents a complete Jager algorithm that can be incorporated into DEM codes and also describes three special provisions for DEM simulations: (1) a method for handling particle pairs that undergo complex tumbling and twirling motions in three-dimensions; (2) a compact data structure for storing the loading history of the many contacts in a large assembly; and (3) an approximation of the Jager algorithm that reduces memory demand. The algorithm addresses contact translations between elastic spheres having identical properties, but it does not resolve the tractions produced by twisting or rolling motions. A performance test demonstrates that the algorithm can be applied in a DEM code with modest increases in computation time but with more substantial increases in required storage. Copyright © 2011 John Wiley & Sons, Ltd.
A general procedure for the esterification of carboxylic acids with diazoalkanes generated in situ by the oxidation of N-tert-butyldimethylsilylhydrazones with (difluoroiodo)benzene

The bimolecular reaction of carboxylic acids with diazoalkanes to form esters is among the mildest and most efficient of organic transformations but is seldom used in synthesis beyond the important case of methyl esterification. This is largely a consequence of the inaccessibility and poor stability of higher diazoalkanes as substrates. In this work we describe a new method for the synthesis of diazoalkanes by the oxidation of N-tert-butyldimethylsilylhydrazones (TBSHs) with (difluoroiodo)benzene, a reagent heretofore unexplored in the context of hydrazone oxidation. When conducted in the presence of a carboxylic acid substrate, the oxidation leads to efficient esterification in situ. In addition to greatly extending the range of diazoalkanes that are now available for esterifications, this new protocol offers significant advantages with regard to safety, for diazo intermediates are neither isolated nor achieve appreciable concentrations during the reaction.
Model reduction for flexible structures - Test data approach

A reduced model of a system is obtained by truncating part of its state variables. Hankel singular values and component costs determine which component is deleted or retained in the reduced model. In this paper Hankel singular values and component costs of a flexible structure are obtained from the resonance test data, rather then from the system matrices. Test data, besides system dynamics, include also actuators and sensors dynamics. For this reason, the reduced model obtained from test data can be far from the optimal one. In this paper the reconstruction of the flexible structure indices from the joint actuator- sensor-flexible structure indices is discussed.
Influence of impeller shroud forces on turbopump rotor dynamics

The shrouded-impeller leakage path forces calculated by Childs (1987) have been analyzed to answer two questions. First, because of certain characteristics of the results of Childs, the forces could not be modeled with traditional approaches. Therefore, an approach has been devised to include the forces in conventional rotordynamic analyses. The forces were approximated by traditional stiffness, damping and inertia coefficients with the addition of whirl-frequency-dependent direct and cross-coupled stiffness terms. The forces were found to be well-modeled with this approach. Finally, the effect these forces had on a simple rotor-bearing system was analyzed, and, therefore, they, in addition to seal forces, were applied to a Jeffcott rotor. The traditional methods of dynamic system analysis were modified to incorporate the impeller forces and yielded results for the eigenproblem, frequency response, critical speed, transient response and an iterative technique for finding the frequency of free vibration as well as system stability. All results lead to the conclusion that the forces have little influence on natural frequency but can have appreciable effects on system stability. Specifically, at higher values of fluid swirl at the leakage path entrance, relative stability is reduced. The only unexpected response characteristics that occurred are attributed to the nonlinearity of the model.
Ppl 15: the first brown dwarf spectroscopic binary

PPl 15 is the first object to have been confirmed as a brown dwarf by the lithium test (in 1995), though its inferred mass was very close to the substellar limit. It is a member of the Pleiades open cluster. Its position in a cluster color-magnitude diagram suggested that it might be binary, and preliminary indications that it is a double-lined spectroscopic binary were reported by us in 1997. Here we report on the results of a consecutive week of Keck HIRES observations of this system, which yield its orbit. It has a period of about 5.8 days, and an eccentricity of 0.4 ± 0.05. The rotation of the stars is slow for this class of objects. Because the system luminosity is divided between two objects with a mass ratio of 0.85, each of them is rendered an incontrovertible brown dwarf, with masses between 60 and 70 MJ. We show that component B is a little redder than A by studying their wavelength-dependent line ratios and that this variation is compatible with the mass ratio. We confirm that the system has lithium but cannot support the original conclusion that it is depleted (which would be surprising, given the new masses). This is a system of very close objects, which, if they had combined, would have produced a low-mass star. We discuss the implications of this discovery for the theories of binary formation and formation of very low mass objects.