cssi/SciSciGPT-SciSciNet huggingface dataset:
Wafer-scale systolic array for adaptive antenna processing

The wafer-scale VLSI system determines the weights for an adaptive antenna application. The data are sampled N-component vector time series X(n), whose components are time functions observed at N individual antenna ports. The processed output, y(n), is a weighted sum of the components, e.g., W/sup t/X(n). The authors expect to compute W about 150 times per second, based on observations of many exponentially windowed samples of X which arrive much more frequently, about 45000 times per second. The algorithm for determining W is based on the use of Givens transformations to rotate the original data into a lower triangular set of linear equations. The computational cost of this algorithm increases with N, the number of degrees of freedom, as N/sup 3/. For sufficiently large N, one must employ some degree of parallelism. The advanced architecture uses /sup N///sub 2/ processors connected in a linear chain, suitable for realizing this algorithm for N=64 in a systolic VLSI wafer-scale design. >
The logic of financial westernization in the Middle East

Abstract In the 19th century, financial reforms in the Middle East included the legalization of interest, the establishment of secular courts, and banking regulations, all based on Western models. Exploring why foreign institutions were transplanted, this article shows that Islamic law blocked evolutionary paths that might have generated financial modernization through indigenous means. Sources of rigidity included (1) the Islamic law of commercial partnerships, which limited enterprise continuity, (2) the Islamic inheritance system, which restrained capital accumulation, (3) the waqf system, which inhibited resource pooling, and (4) Islam's traditional aversion to the concept of legal personhood, which hampered private organizations.
ETA: experience with an Intel Xeon processor as a packet processing engine

Server-based networks have well-documented performance limitations. These limitations outline a major goal of Intel's embedded transport acceleration (ETA) project, the ability to deliver high-performance server communication and I/O over standard Ethernet and transmission control protocol/Internet protocol (TCP/IP) networks. By developing this capability, Intel hopes to take advantage of the large knowledge base and ubiquity of these standard technologies. With the advent of 10 gigabit Ethernet, these standards promise to provide the bandwidth required of the most demanding server applications. We use the term packet processing engine (PPE) as a generic term for the computing and memory resources necessary for communication-centric processing. Such PPEs have certain desirable attributes; the ETA project focuses on developing PPEs with such attributes, which include scalability, extensibility, and programmability. General-purpose processors, such as the Intel Xeon in our prototype, are extensible and programmable by definition. Our results show that software partitioning can significantly increase the overall communication performance of a standard multiprocessor server. Specifically, partitioning the packet processing onto a dedicated set of compute resources allows for optimizations that are otherwise impossible when time sharing the same compute resources with the operating system and applications.
The Affections and the Passions Their Economic Logic

Two types of emotions can be distinguished: the affections (stable patterns of malevolence or benevolence toward particular others) and the passions (action-dependent responses to friendly/unfriendly acts). Either type may serve to induce cooperation from a self-interested party, subject to several limitations. Shakespeare's King Lear is examined as an instance where benevolence fails to elicit cooperation. To meet the necessary condition for evolutionary survival in competition with rational self-interested players, the emotional party must benefit not only in “feel good” utility terms but in actual material payoff. SILVER RULE, as an instance of reactive passionate behavior related to the familiar TIT FOR TAT behavior, is shown to lose out in evolutionary competition against RATIONAL play unless the SILVER RULE player has a sufficiently high probability of being able to detect when his opponent is a selfish RATIONAL player.
Pension reform, financial literacy and public information : a case study of the United Kingdom

This paper, the first in a series on public information, and pension reform to explore issues examining a range of country experiences, looks at the experience in the United Kingdom (UK), where a number of initiatives to improve general, and individual pension information, are described, and assessed. The UK pension system is briefly described, to then focus on the consumer knowledge of pensions, and the lack of confidence in a complex and rapidly changing pension system, indifference to retirement-income planning, and problems in getting trustworthy advice. Current and planned initiatives to improve both general pensions, and financial knowledge and information about individual pension rights, - from government financial regulators, and the private sector - are then assessed. Pension reforms in the UK emphasize private funding, rather than state, pay-as-you-go provision, promote defined-contribution, rather than defined-benefit schemes, and in particular they should lead to lower administrative charges with private pensions, and greater flexibility in changing contribution levels as family finances require. The report highlights the importance of the role of public information in preparing for, and promoting reform, in ensuring people understand the choices open to them, and the decisions they are expected to make, but mostly, public information should address, and ensure the understanding of the pension system.
CoFD: An Algorithm for Non-distance Based Clustering in High Dimensional Spaces

The clustering problem, which aims at identifying the distribution of patterns and intrinsic correlations in large data sets by partitioning the data points into similarity clusters, has been widely studied. Traditional clustering algorithms use distance functions to measure similarity and are not suitable for high dimensional spaces. In this paper, we propose CoFD algorithm, which is a non-distance based clustering algorithm for high dimensional spaces. Based on the maximum likelihood principle, CoFD is to optimize parameters to maximize the likelihood between data points and the model generated by the parameters. Experimental results on both synthetic data sets and a real data set show the efficiency and effectiveness of CoFD.
Formation and diffusion of S-decorated Cu clusters on Cu(111).

Because of their strong internal bonding, S-decorated Cu trimers are a likely agent of S-enhanced Cu transport between islands on Cu(111). According to ab-initio calculations, excellent healing of dangling Cu valence results in an ad-Cu{sub 3}S{sub 3} formation energy of only {approximately}0.28 eV, compared to 0.79 eV for a self-adsorbed Cu atom, and a diffusion barrier {le}0.35 eV.
Modeling genome evolution with a diffusion approximation of a birth-and-death process

Motivation: In our previous studies, we developed discrete-space birth, death and innovation models (BDIMs) of genome evolution. These models explain the origin of the characteristic Pareto distribution of paralogous gene family sizes in genomes, and model parameters that provide for the evolution of these distributions within a realistic time frame have been identified. However, extracting the temporal dynamics of genome evolution from discrete-space BDIM was not technically feasible. We were interested in obtaining dynamic portraits of the genome evolution process by developing a diffusion approximation of BDIM. Results: The diffusion version of BDIM belongs to a class of continuous-state models whose dynamics is described by the Fokker--Plank equation and the stationary solution could be any specified Pareto function. The diffusion models have time-dependent solutions of a special kind, namely, generalized self-similar solutions, which describe the transition from one stationary distribution of the system to another; this provides for the possibility of examining the temporal dynamics of genome evolution. Analysis of the generalized self-similar solutions of the diffusion BDIM reveals a biphasic curve of genome growth in which the initial, relatively short, self-accelerating phase is followed by a prolonged phase of slow deceleration. This evolutionary dynamics was observed both when genome growth started from zero and proceeded via innovation (a potential model of primordial evolution), and when evolution proceeded from one stationary state to another. In biological terms, this regime of evolution can be tentatively interpreted as a punctuated-equilibrium-like phenomenon whereby evolutionary transitions are accompanied by rapid gene amplification and innovation, followed by slow relaxation to a new stationary state. Contact: koonin@ncbi.nlm.nih.gov
Extended Unemployment Insurance and Job Search: Evidence from Time Use Data

In this paper, I investigate the effect of extended unemployment insurance (UI) coverage in the United States in recent years on job search. The U.S. government extended UI benefits in several phases in 2008–2009, increasing the duration of the benefits to a maximum of 99 weeks, up from the regular 26 weeks. Using the American Time Use Survey (ATUS) data, I find that women are more sensitive to the extended UI benefits than men. Difference-in-differences estimation shows that the average effect of the UI extensions for women is over a 10 percentage points decline in the probability of job search. However, I do not find any statistically significant effect on men.
Dynamical systems that sort lists, diagonalize matrices, and solve linear programming problems

Abstract We establish a number of properties associated with the dynamical system H = [H,[H, N]] , where H and N are symmetric n by n matrices and [ A , B ] = AB − BA . The most important of these come from the fact that this equation is equivalent to a certain gradient flow on the space of orthogonal matrices. We are especially interested in the role of this equation as an analog computer. For example, we show how to map the data associated with a linear programming problem into H (0) and N in such a way as to have H = [H[H, N]] evolve to a solution of the linear programming problem. This result can be applied to find systems which solve a variety of genetic combinatorial optimization problems, and it even provides an algorithm for diagonalizing symmetric matrices.
Completion Time and Response Order Effects in Web Surveys

The use of the World Wide Web to conduct surveys has grown rapidly over the past decade, raising concerns regarding data qual- ity, questionnaire design, and sample representativeness. This research note focuses on an issue that has not yet been studied: Are respondents who complete self-administered Web surveys more quickly—perhaps taking advantage of participation benefits while minimizing effort—also more prone to response order effects, a manifestation of "satisficing"? I surveyed a random sample of the US adult population over the Web and manipulated the order in which respondents saw the response options. I then assessed whether primacy effects were moderated by the overall length of time respondents took to complete the questionnaires. I found that low-education respondents who filled out the questionnaire most quickly were most prone to primacy effects when completing items with unipolar rating scales. These results have important implications for var- ious aspects of Web survey methodology including panel management, human-computer interaction, and response order randomization.
An efficient context-free parsing algorithm

A parsing algorithm which seems to be the most efficient general context-free algorithm known is described. It is similar to both Knuth's LR(k) algorithm and the familiar top-down algorithm. It has a time bound proportional to n3 (where n is the length of the string being parsed) in general; it has an n2 bound for unambiguous grammars; and it runs in linear time on a large class of grammars, which seems to include most practical context-free programming language grammars. In an empirical comparison it appears to be superior to the top-down and bottom-up algorithms studied by Griffiths and Petrick.
Output Feedback Variable Structure Adaptive Control of a Flexible Spacecraft

Abstract Based on the variable structure model reference adaptive control theory, a new control system for the control of an orbiting flexible spacecraft, using output feedback, is designed. The spacecraft consists of a main rigid body to which elastic appendages are attached. For the purpose of control, a moment generating device is located on the rigid hub. For the derivation of control law, it is assumed that the parameters and the structure of the nonlinear functions in the model are unknown. It is shown that in the closed-loop system including the variable structure model reference adaptive control system designed using bounds on uncertain functions, the pitch angle tracks given reference trajectory and the vibration is suppressed. Digital simulation results show that the closed-loop system has good transient behavior and robustness to the uncertainties, unmodeled dynamics, and disturbance inputs.
On maximizing the convergence rate for linear systems with input saturation

In this note, we consider a few important issues related to the maximization of the convergence rate inside a given ellipsoid for linear systems with input saturation. For continuous-time systems, the control that maximizes the convergence rate is simply a bang-bang control. Through studying the system under the maximal convergence control, we reveal several fundamental results on set invariance. An important consequence of maximizing the convergence rate is that the maximal invariant ellipsoid is produced. We provide a simple method for finding the maximal invariant ellipsoid, and we also study the dependence of the maximal convergence rate on the Lyapunov function.
Query-by-example: operations on hierarchical data bases

Query-by-Example is a high level non-procedural data base language which provides the end user with a simplified unified interface for querying, updating, defining, and maintaining, the data base, as well as imbedding various integrity and authority constraints. When querying the data base the user fills in, through a keyboard display, an example of a possible answer in a skeleton of the logical structure of the data base. As demonstrated in previous work, when the data base is relational, skeleton tables are used. In this paper, we show that the Query-by-Example operations are in fact independent of the structure of the data base. In particular, we demonstrate that if the view at the user interface level is hierarchical, the query is again accomplished by filling-in an example of a possible answer, but, in this case, a skeleton of the hierarchy is utilized. It is, also, shown how the user can map a relational view into a hierarchical view and vice versa, formulating queries that involve both views simultaneously. Finally, a linear version of Query-by-Example is made available for situations where a display facility is unavailable.
Assessing Potential Glycemic Overtreatment in Persons at Hypoglycemic Risk

Importance Although serious hypoglycemia is a common adverse drug event in ambulatory care, current performance measures do not assess potential overtreatment. Objective To identify high-risk patients who had evidence of intensive glycemic management and thus were at risk for serious hypoglycemia. Design, Setting, and Participants Cross-sectional study of patients in the Veterans Health Administration receiving insulin and/or sulfonylureas in 2009. Main Outcomes and Measures Intensive control was defined as the last hemoglobin A 1c (HbA 1c ) measured in 2009 that was less than 6.0%, less than 6.5%, or less than 7.0%. The primary outcome measure was an HbA 1c less than 7.0% in patients who were aged 75 years or older who had a serum creatinine value greater than 2.0 mg/dL or had a diagnosis of cognitive impairment or dementia. We also assessed the rates in patients with other significant medical, neurologic, or mental comorbid illness. Variation in rates of possible glycemic overtreatment was evaluated among 139 Veterans Health Administration facilities grouped within 21 Veteran Integrated Service Networks. Results There were 652 378 patients who received insulin and/or a sulfonylurea with an HbA 1c test result. Fifty percent received sulfonylurea therapy without insulin; the remainder received insulin therapy. We identified 205 857 patients (31.5%) as the denominator for the primary outcome measure; 11.3% had a last HbA 1c value less than 6.0%, 28.6% less than 6.5%, and 50.0% less than 7.0%. Variation in rates by Veterans Integrated Service Network facility ranged 8.5% to 14.3%, 24.7% to 32.7%, and 46.2% to 53.4% for HbA 1c less than 6.0%, less than 6.5%, and less than 7.0%, respectively. The magnitude of variation by facility was larger, with overtreatment rates ranging from 6.1% to 23.0%, 20.4% to 45.9%, and 39.7% to 65.0% for HbA 1c less than 6.0%, less than 6.5%, and less than 7.0%, respectively. The maximum rate was nearly 4-fold compared with the minimum rates for HbA 1c less than 6.0%, followed by 2.25-fold for HbA 1c less than 6.5% and less than 2-fold for HbA 1c less than 7.0%. When comorbid conditions were included, 430 178 patients (65.9%) were identified as high risk. Rates of overtreatment were 10.1% for HbA 1c less than 6.0%, 25.2% for less than 6.5%, and 44.3% for less than 7.0%. Conclusions and Relevance Patients with risk factors for serious hypoglycemia represent a large subset of individuals receiving hypoglycemic agents; approximately one-half had evidence of intensive treatment. A patient safety indicator derived from administrative data can identify high-risk patients for whom reevaluation of glycemic management may be appropriate, consistent with meaningful use criteria for electronic medical records.
Computational Analysis of the Accession of Chile to the NAFTA and Western Hemisphere Integration

We present the results based on the Michigan computational general equilibrium model of Western Hemisphere economic integration. It is shown that tariff elimination will have beneficial effects for most countries involved, although the benefits as well as the costs of liberalizatio n are small. However, if a hemispheric treaty were to stimulate an increase in the capital stocks of the major South American economies, the welfare gains would be substantial. Sensitivity tests reveal that the model exaggerates the likely gains from economies of scale due to liberalization. But the error is small in this context because the impact of trade liberalization is small. When econometric estimates of scale economies are incorporated into the model, the welfare gains due to capital flows nevertheless remain robust. A comparison of results for Chile using different databases indicates that the impact of regional liberalization using a 1980 database may overstate the impact on the nonferrous metals sector in particular and manufacturing more generally. Nonetheless, when using a 1990 database, the change in output of the nonferrous metals sector remain larger than for any other sectors in the Chilean economy.
Certifying controls and systems software

Software system certification presents itself with many challenges, including the necessity to certify the system at the level of functional requirements, code and binary levels, the need to chase down run-time errors, and the need for proving timing properties of the eventual, compiled system. This paper illustrates possible approaches for certifying code that arises from control systems requirements as far as stability properties are concerned. The relative simplicity of the certification process should encourage the development of systematic procedures for certifying control system codes for more complex environments.
The crystal structure and magnetic properties of a new ferrimagnetic semiconductor: Ca21Mn4Sb18.

Single crystals of the new transition metal Zintl phase, Ca21Mn4Sb18, were prepared by high temperature melt synthesis. The crystal structure was determined by single crystal X-ray diffraction to be monoclinic in the space group C2/c. Crystal information was obtained at 90 K, and unit cell parameters were determined (a = 17.100(2) A, b = 17.073(2) A, c = 16.857(2) A, β = 92.999(2)°, Z = 2, R1 = 0.0540, wR2 = 0.1437). The structure can be described as containing 4 discreet units per formula unit: 1 linear [Mn4Sb10]22- anion, 2 dumbbell-shaped [Sb2]4- anions, 4 individual Sb3- anions, and 21 Ca2+ cations. The [Mn4Sb10]22- anion contains four edge-shared MnSb4 tetrahedra with distances between Mn ions of 3.388(4) A, 2.782(4) A, and 2.760(4) A. Electron counting suggests that the Mn are 2+. Temperature dependent magnetization shows a ferromagnetic-like transition temperature at ∼52 K which is suppressed with increasing magnetic field. The paramagnetic regime is best fit to a ferrimagnetic model, providing a ...
Probabilistic basis and assessment methodology for effectiveness of protecting nuclear materials

Safeguards and security systems for nuclear facilities include material control and accounting (MC&A) and a physical protection system (PPS) to protect against theft, sabotage and other malevolent human acts. The insider threat is most often addressed as part of the evaluation of a facility's PPS. A PPS is evaluated using probabilistic analysis of adversary paths on the basis of detection, delay, and response timelines to determine timely detection. Because insider adversaries have access to, knowledge of, and authority for facility operations, the PPS actually provides minimal protection against the insider threat. By monitoring and tracking critical materials, MC&A activities are an important protection element against inside adversaries. Timely detection for MC&A activities, however, has been difficult to determine so that for the most part, the effectiveness of these activities has not been explicitly incorporated in the insider threat evaluation of a PPS. This paper presents research on a new approach to incorporate MC&A protection elements explicitly within the existing probabilistic path analysis methodology. MC&A activities, from monitoring to inventory measurements, provide many, often recurring opportunities to determine the status of critical items, including detection of missing materials. Human reliability analysis methods for nuclear power plant operations are used to determine human error probabilities to characterize the detection capabilities of MC&A activities. An object-based state machine paradigm was developed to characterize the path elements and timing of an insider theft scenario as a race against MC&A detection that can move a facility from a normal state to an alert state having additional detection opportunities. Event sequence diagrams describe insider paths through the PPS and also incorporate MC&A activities as path elements. To address the insider threat, this work establishes a probabilistic basis for timely MC&A detection and methods to evaluate the effectiveness of MC&A activities explicitly within the existing path analysis methodology.
The Challenge of Assuring Data Trustworthiness

With the increased need of data sharing among multiple organizations, such as government organizations, financial corporations, medical hospitals and academic institutions, it is critical to ensure that data is trustworthy so that effective decisions can be made based on these data. In this paper, we first discuss motivations and requirement for data trustworthiness. We then present an architectural framework for a comprehensive system for trustworthiness assurance. We then discuss an important issue in our framework, that is, the evaluation of data provenance and survey a trust model for estimating the confidence level of the data and the trust level of data providers. By taking into account confidence about data provenance, we introduce an approach for policy observing query evaluation. We highlight open research issues and research directions throughout the paper.
Practical synthesis and applications of benzoboroxoles

Abstract A convenient one-pot synthesis of benzoboroxoles has been developed via the reaction of o-bromobenzyl alcohols with NaH, nBuLi, and B(OiPr)3 followed by acidic hydrolysis. Applications of these benzoboroxoles have been demonstrated in Pd-catalyzed cross-coupling reactions and the protocol has been extended for the synthesis of a chiral benzoboroxole. Exceptionally short synthesis of a potent antifungal agent AN2690 and several of its analogs has also been realized.
Scanning electron microscopy of heinz bodies in feline erythrocytes.

Whole blood and partially lysed blood films from 5 cats having 20 to 91% of the erythrocytes containing Heinz bodies were examined, using the light microscope and the scanning electron microscope. Heinz bodies were detected in the intact erythrocytes from 3 of the cats as abruptly elevated and distinctly demarcated protuberances in various shapes, sizes, and locations. The Heinz bodies were located just beneath the cell membrane either centrally or near the cell margin and varied in their projectional magnitude. Brilliant cresyl blue staining of blood of these 3 cats revealed prominent Heinz bodies within, and projecting from, the erythrocytes. In contrast, Heinz bodies were not identified on scanning electron microscopy of intact erythrocytes of the remaining 2 cats even though Heinz bodies were found on their blood films stained with brilliant cresyl blue. Scanning electron microscopy of partially lysed blood smears of all 5 cats revealed Heinz bodies of various sizes in the erythrocyte ghosts. Furthermore, blood smears from the 3 cats having distinct Heinz bodies in intact erythrocytes revealed small dense intracellular granules distributed singly or coalesced in small clumps. Further aggregation of these clumps was assumed to result in the formation of a single large Heinz body. The 3-dimensional nature of Heinz bodies was clearly apparent in lysed blood smears.
Stochastic system identification with noisy input-output measurements using polyspectra

Two new classes of parametric, frequency domain approaches are proposed for estimation of the parameters of scalar, linear "errors-in-variables" models, i.e., linear systems where measurements of both input and output of the system are noise contaminated. The first approach consists of linear estimators where using the bispectrum or the integrated polyspectrum of the input and the cross-bispectrum or the integrated cross-polyspectrum, the system transfer function is first estimated at a number of frequencies exceeding one-half the number of unknown parameters. The estimated transfer function is then used to estimate the unknown parameters using an overdetermined linear system of equations. In the second class of approaches, quadratic transfer function matching criteria are optimized by using the results of the linear estimators as initial guesses. Both classes of the parameter estimators are shown to be consistent in any measurement noise that has symmetric probability density function when the bispectral approaches are used. The proposed parameter estimators are shown to be consistent in Gaussian measurement noise when trispectral approaches are used. >
Field experience with an SRB rapid detection test kit

This paper reports field experience with a new rapid method to detect and count sulfate-reducing bacteria (SRB) accurately. Test results are available in 15 minutes, compared with the 3 to 4 weeks required with traditional culture methods. This new test method detects SRB that grow poorly or not at all on culture media and gives superior results with such solids samples as biofilms, soils, and sludge.
Highly coherent injection-locked laser diode arrays.

Two physically separated laser diode arrays were simultaneously injection-locked to the same master laser. The modulus of their mutual coherence function was measured, and the resulting value 0.96 ± 0.06 was close to the maximum allowed value of 1. The spatial phase of the two injection-locked outputs did not vary from each other by more than 0.05 wave (λ/20), apart from a phase difference that grew linearly with position, due to the tilt between the two interfering beams. Requirements for the coherent combination of injection-locked laser diode arrays are discussed.
Enantioselective Total Synthesis of (−)-Pironetin: Iterative Aldol Reactions of Thiazolidinethiones

The enantioselective total synthesis of pironetin has been achieved in 11 steps from known aldehyde 2. The synthesis relies on the formation of 5 out of 6 stereocenters through titanium mediated iterative aldol reactions. Key steps in this synthesis include an acetal aldol reaction to establish the stereochemistry at C8 and C9, an acetate aldol reaction, and “Evans” syn aldol reaction.
Harem-male replacement and infanticide in the blue monkey (Cercopithecus mitus stuhlmanni) in the Kibale Forest, Uganda.

This paper (1) describes the first observations of male replacement and infanticide in the blue monkey (Cercopithecus mitis stuhlmanni), (2) examines these observations in light of those hypotheses put forth to explain infanticide, and (3) presents two basic models through which additional hypotheses are developed. Five groups of blue monkeys were observed for 2,724 hr in the Kibale Forest, Uganda. The pattern of infanticide in the blue monkey was strikingly similar to that reported for other species of primates living in one-male bisexual groups. Data concerning infanticide in the blue monkey do not support the hypothesis that infanticide is a maladaptive behavioral pathology. The data indirectly support the hypothesis that infanticide is part of a flexible, adaptive reproductive strategy of new harem-males. According to Model I, two of the hypothese for explaining how infanticide may be adaptive to the perpetrator are not mutually exclusive. Model II suggests that the rate of infanticide is directly related to competition among males for females and indirectly related to tenure length of harem-males. Models I and II underscore the importance of understanding what variables determine tenure length in haremmales. It is cocluded that length of male tenure is most likely a critical determinant of inclusive fitness not only for males but also for females.
Guessing Facets: Polytope Structure and Improved LP Decoder

A new approach for decoding binary linear codes by solving a linear program (LP) over a relaxed codeword polytope was recently proposed by Feldman et al. In this paper we investigate the structure of the polytope used in the LP relaxation decoding. We begin by showing that for expander codes, every fractional pseudocodeword always has at least a constant fraction of non-integral bits. We then prove that for expander codes, the active set of any fractional pseudocodeword is smaller by a constant fraction than the active set of any codeword. We exploit this fact to devise a decoding algorithm that provably outperforms the LP decoder for finite blocklengths. It proceeds by guessing facets of the polytope, and resolving the linear program on these facets. While the LP decoder succeeds only if the ML codeword has the highest likelihood over all pseudocodewords, we prove that for expander codes the proposed algorithm succeeds even with a constant number of pseudocodewords of higher likelihood. Moreover, the complexity of the proposed algorithm is only a constant factor larger than that of the LP decoder.
An Outer Bound to the Capacity Region of the Broadcast Channel

An outer bound to the capacity region of the two-receiver discrete memoryless broadcast channel is given. The outer bound is tight for all cases where the capacity region is known. When specialized to the case of no common information, this outer bound is shown to be contained in the Korner-Marton outer bound. This containment is shown to be strict for the binary skew-symmetric broadcast channel. Thus, this outer bound is in general tighter than all other known outer bounds on the discrete memoryless broadcast channel.
Feed-forward transient current control for low-voltage ride-through enhancement of DFIG wind turbines

High penetration of wind power requires reliable wind energy generation. A successful low-voltage ride-through (LVRT) scheme is a key requirement to achieve reliable and uninterrupted electrical power generation for wind turbines equipped with doubly fed induction generators (DFIGs). This paper proposes a feed-forward transient current control (FFTCC) scheme for the rotor side converter (RSC) of a DFIG to enhance its LVRT capability. This new control scheme introduces additional feed-forward transient compensations to a conventional current regulator. When three phase faults occur, these compensation terms correctly align the RSC ac-side output voltage with the transient-induced voltage, resulting in minimum transient rotor current and minimum occurrence of crowbar interruptions. With little additional computational effort, the proposed control scheme helps relieve the transient current stress on the RSC and helps maintain an uninterrupted active and reactive power supply from the wind turbines to the power grid. Simulation results are shown to demonstrate the effectiveness of the proposed FFTCC scheme in suppressing transient rotor currents.
QoS Analysis of Cognitive Radio Channels with Perfect CSI at Both Receiver and Transmitter

In this paper, cognitive transmission under quality of service (QoS) constraints is studied. In the cognitive radio channel model, it is assumed that both the secondary receiver and the secondary transmitter know the channel fading coefficients perfectly and optimize the power adaptation policy under given constraints, depending on the channel activity of the primary users, which is determined by channel sensing performed by the secondary users. The transmission rates are equal to the instantaneous channel capacity values. A state transition model with four states is constructed to model this cognitive transmission channel. Statistical limitations on the buffer lengths are imposed to take into account the QoS constraints. The maximum throughput under these statistical QoS constraints is identified by finding the effective capacity of the cognitive radio channel. The impact upon the effective capacity of several system parameters, including the channel sensing duration, detection threshold, detection and false alarm probabilities, and QoS parameters, is investigated.
The impact of QoS constraints on the energy efficiency of fixed-rate wireless transmissions

Transmission over wireless fading channels under quality of service (QoS) constraints is studied when only the receiver has channel side information. Being unaware of the channel conditions, transmitter is assumed to send the information at a fixed rate. Under these assumptions, a two-state (ON-OFF) transmission model is adopted, where information is transmitted reliably at a fixed rate in the ON state while no reliable transmission occurs in the OFF state. QoS limitations are imposed as constraints on buffer violation probabilities, and effective capacity formulation is used to identify the maximum throughput that a wireless channel can sustain while satisfying statistical QoS constraints. Energy efficiency is investigated by obtaining the bit energy required at zero spectral efficiency and the wideband slope in both wideband and low-power regimes assuming that the receiver has perfect channel side information (CSI). Initially, the wideband regime with multipath sparsity is investigated, and the minimum bit energy and wideband slope expressions are found. It is shown that the minimum bit energy requirements increase as the QoS constraints become more stringent. Subsequently, the low-power regime, which is also equivalent to the wideband regime with rich multipath fading, is analyzed. In this case, bit energy requirements are quantified through the expressions of bit energy required at zero spectral efficiency and wideband slope. It is shown for a certain class of fading distributions that the bit energy required at zero spectral efficiency is indeed the minimum bit energy for reliable communications. Moreover, it is proven that this minimum bit energy is attained in all cases regardless of the strictness of the QoS limitations. The impact upon the energy efficiency of multipath sparsity and richness is quantified, and comparisons with variable-rate/fixed-power and variable-rate/variable-power cases are provided.
p-p′ Strings in M(atrix) theory

Abstract We study the off-diagonal blocks in the M(atrix) model that are supposed to correspond to open strings stretched between a D p -brane and a D p ′-brane. It is shown that the spectrum, including the quantum numbers, of the zero-modes in the off-diagonal blocks can be determined from the index theorem and unbroken supersymmetry, and indeed reproduces string theory predictions for p - p ′ strings. Previously the matrix description of a longitudinal fivebrane needed the introduction of extra degrees of freedom corresponding to 0–4 strings by hand. We show that they are naturally associated with the off-diagonal zero-modes, and the supersymmetry transformation laws and low-energy effective action postulated for them are now derivable from the M(atrix) theory.
Buckling Behavior of Long Anisotropic Plates Subjected to Fully Restrained Thermal Expansion

An approach for synthesizing buckling results for, and behavior of, thin balanced and unbalanced symmetric laminates that are subjected to uniform heating or cooling and elastically restrained against thermal expansion or contraction is presented. This approach uses a nondimensional analysis for infinitely long, flexurally anisotropic plates that are subjected to combined mechanical loads and is based on useful nondimensional parameters. In addition, stiffness-weighted laminate thermal-expansion parameters and compliance coefficients are derived that are used to determine critical temperatures in terms of physically intuitive mechanical-buckling coefficients. The effects of membrane orthotropy and membrane anisotropy are included in the general formulation. Many results are presented for some common laminates that are intended to facilitate a structural designer's transition to the use of generic buckling design curves. Several curves that illustrate the fundamental parameters used in the analysis are presented, for nine contemporary material systems, that provide physical insight into the buckling response in addition to providing useful design data. Examples are presented that demonstrate the use of generic design curves. The analysis approach and generic results indicate the effects and characteristics of elastically restrained laminate thermal expansion or contraction, membrane orthotropy and anisotropy, and flexural orthotropy and anisotropy in a very general and unifying manner.
Efficient stereoselective synthesis of oligosaccharides of Streptococcus pneumoniae serotypes 6A and 6B containing multiple 1,2-cis glycosidic linkages

Abstract The synthesis of the repeating units of pneumococcal polysaccharide serotypes 6A and 6B and derivatives thereof is described. Application of S-benzoxazolyl and S-thiazolinyl glycosides allowed rapid oligosaccharide assembly and provided complete stereoselectivity in challenging 1,2-cis glucosylations and galactosylations. The oligosaccharide assembly was accomplished in an efficient manner by selective activation of thioimidoyl leaving groups over thioglycosides.
Networks Inferred from Biochemical Data Reveal Profound Differences in Toll-like Receptor and Inflammatory Signaling between Normal and Transformed Hepatocytes

Systematic study of cell signaling networks increasingly involves high throughput proteomics, transcriptional profiling, and automated literature mining with the aim of assembling large scale interaction networks. In contrast, functional analysis of cell signaling usually focuses on a much smaller sets of proteins and eschews computation but focuses directly on cellular responses to environment and perturbation. We sought to combine these two traditions by collecting cell response measures on a reasonably large scale and then attempting to infer differences in network topology between two cell types. Human hepatocytes and hepatocellular carcinoma cell lines were exposed to inducers of inflammation, innate immunity, and proliferation in the presence and absence of small molecule drugs, and multiplex biochemical measurement was then performed on intra- and extracellular signaling molecules. We uncovered major differences between primary and transformed hepatocytes with respect to the engagement of toll-like receptor and NF-κB-dependent secretion of chemokines and cytokines that prime and attract immune cells. Overall, our results serve as a proof of principle for an approach to network analysis that is systematic, comparative, and biochemically focused. More specifically, our data support the hypothesis that hepatocellular carcinoma cells down-regulate normal inflammatory and immune responses to avoid immune editing.
Economic Growth and Political Regimes

The absence of continuous regime type measures that focus on institutions rather than outcomes besets studies on whether democratic or authoritarian regimes grow faster. Additional shortcomings include the failure to consider development stages and the erroneous endogenous specification of regimes. Given panel data on 105 countries from 1960 to 1989, the effective party/constitutional framework measure does not correlate with growth or investment in the total sample. But considering development levels, some evidence indicates that discretion decreases growth in advanced areas, and, contrary to theory, inhibits investment in poorer countries. Also, single-party dictatorships have higher investment ratios but do not grow faster than party-less regimes.
The concept of “character” in Dirichlet’s theorem on primes in an arithmetic progression

In 1837, Dirichlet proved that there are infinitely many primes in any arithmetic progression in which the terms do not all share a common factor. We survey implicit and explicit uses of Dirichlet characters in presentations of Dirichlet’s proof in the nineteenth and early twentieth centuries, with an eye toward understanding some of the pragmatic pressures that shaped the evolution of modern mathematical method.
SHASTRA — AN ARCHITECTURE FOR DEVELOPMENT OF COLLABORATIVE APPLICATIONS

We address the issue of architectures and abstractions to implement multimedia scientific manipulation systems in a Concurrent Engineering setting, where experts in a cooperating group communicate and interact to solve problems. We propose a model for the integration of software tools into a multi-user distributed and collaborative environment on the multimedia desktop, and describe a prototype CSCW infrastructure which we have used to implement scientific problem solving tools. Finally, we briefly describe a prototype CE system built on this infrastructure. Shastra presents a unified prototype for some crucial enabling technologies for Concurrent Engineering — Multimedia Communication, Framework Integration, Coordination, and Enterprise Integration.
Integral equations with hypersingular kernels––theory and applications to fracture mechanics

Abstract Hypersingular integrals of the type I α (T n ,m,r)= −1 1 T n (s)(1−s 2 ) m−1/2 (s−r) α d s, |r| and I α (U n ,m,r)= −1 1 U n (s)(1−s 2 ) m−1/2 (s−r) α d s, |r| are investigated for general integers α (positive) and m (nonnegative), where Tn(s) and Un(s) are the Chebyshev polynomials of the first and second kinds, respectively. Exact formulas are derived for the cases α=1,2,3,4 and m=0,1,2,3; most of them corresponding to new solutions derived in this paper. Moreover, a systematic approach for evaluating these integrals when α>4 and m>3 is provided. The integrals are also evaluated as |r|>1 in order to calculate the stress intensity factors. Examples involving crack problems are given and discussed with emphasis on the linkage between mathematics and mechanics of fracture. The examples include classical linear elastic fracture mechanics, functionally graded materials, and gradient elasticity theory. An appendix, with an alternative derivation of the formulae, supplements the paper.
Binary compounds of boron and beryllium: a rich structural arena with space for predictions.

We explore ground-state structures and stoichiometries of the BeB system in the static limit, with Be atom concentrations of 20 % or greater, and from P = 1 atm up to 320 GPa. At P = 1 atm, predictions are offered for several known compounds, the structures of which have not yet been determined experimentally. Spe- cifically, at 1 atm, we predict a struc- ture of R3 ¯ m symmetry for the com- pound Be2B3, seen experimentally at high temperatures, which contains in- teresting BeBBBBe rods; and for the compound BeB4 we calculate metasta- bility with respect to the elements with a structure similar to MgB4, which is quickly replaced as the pressure is ele- vated by a Cmcm structure that fea- tures 6- and 4-membered rings in B cages, with Be interstitials. For another high-temperature compound, Be2B, we confirm the CaF2 structure, but find a competitive and actually slightly more stable ground-state structure of C2/m symmetry that features B2 pairs. In the case of BeB2, a material for which the stoichiometry has been the subject of debate, we have a clear prediction of a stable F4 ¯ 3m structure at P = 1 atm. It has a diamondoid structure that is based on cubic (lower P) or hexagonal (higher P) diamond networks of B, but with Be in the interstices. This Zintl structure is a semiconductor at low and intermediate pressures. At higher pres- sures, BeB2 dominates the phase dia- gram. In general, the Zintl-Klemm concept of effective electron transfer from the more electropositive ion and bond formation among the resulting anions has proven useful in analyzing the structural preferences of many compositions in the BeB system at P = 1 atm and at elevated pressures. An unusual feature of this binary system is that the 1:1 BeB stoichiometry never appears to reach stability in the static limit, although it comes close, as does Be17B12. Also stable at high pressures are stoichiometries BeB3 ,B eB 4, and Be5B2.
Analyzing and Visualizing Cosmological Simulations with ParaView

The advent of large cosmological sky surveys—ushering in the era of precision cosmology—has been accompanied by ever larger cosmological simulations. The analysis of these simulations, which currently encompass tens of billions of particles and up to a trillion particles in the near future, is often as daunting as carrying out the simulations in the first place. Therefore, the development of very efficient analysis tools combining qualitative and quantitative capabilities is a matter of some urgency. In this paper, we introduce new analysis features implemented within ParaView, a fully parallel, open-source visualization toolkit, to analyze large N-body simulations. A major aspect of ParaView is that it can live and operate on the same machines and utilize the same parallel power as the simulation codes themselves. In addition, data movement is in a serious bottleneck now and will become even more of an issue in the future; an interactive visualization and analysis tool that can handle data in situ is fast becoming essential. The new features in ParaView include particle readers and a very efficient halo finder that identifies friends-of-friends halos and determines common halo properties, including spherical overdensity properties. In combination with many other functionalities already existing within ParaView, such as histogram routines or interfaces to programming languages like Python, this enhanced version enables fast, interactive, and convenient analyses of large cosmological simulations. In addition, development paths are available for future extensions.