cssi/SciSciGPT-SciSciNet huggingface dataset:
Measurement and Modeling of the Economic Effects of Trade and Investment Barriers in Services

In this paper, we adapt the latest version of the Michigan Model of World Production and Trade to incorporate relationships and data for cross-border services trade and foreign direct investment (FDI) in the major developed and developing countries subsumed in the model’s structure and database. Firms are taken to be monopolistically competitive. Each firm produces a set of differentiated products. Products are differentiated both by the original R&D undertaken at headquarters that defines the basic product and by the final location of production. Each firm faces a fixed cost in the country where production occurs, and it then sets an optimal mark-up of price over marginal cost for sales from each location. Free entry guarantees that profits are zero. Firms locate production for export or for local consumption depending on the type of barriers restraining the conduct of multinationals. In this version of the model, barriers to trade in services take two forms. First, firms may face an ad valorem tax on local capital installed. Second, foreign affiliate firms may face a policy-induced fixed cost of production for local operations. We report the impact on welfare, trade, factor prices, sectoral output, economies of scale, and activities of multinationals that might occur following the introduction of national treatment of multinational firms in all countries of the model.
Where Everybody Knows Your (Screen) Name: Online Games as “Third Places”

This article examines the form and function of massively multiplayer online games (MMOs) in terms of social engagement. Combining conclusions from media effects research informed by the communication effects literature with those from ethnographic research informed by a sociocultural perspective on cognition and learning, we present a shared theoretical framework for understanding (a) the extent to which such virtual worlds are structurally similar to ‘‘third places’’ (Oldenburg, 1999) for informal sociability, and (b) their potential function in terms of social capital (Coleman, 1988; Putnam, 2000). Our conclusion is that by providing spaces for social interaction and relationships beyond the workplace and home, MMOs have the capacity to function as one form of a new ‘‘third place’’ for informal sociability. Participation in such virtual ‘‘third places’’ appears particularly well suited to the formation of bridging social capital—social relationships that, while not usually providing deep emotional support, typically function to expose the individual to a diversity of worldviews.
Do performance agreements help improve service delivery ? the experience of Brazilian states

A growing number of states and municipalities in Brazil rely on results-based management, and many other local and state governments are considering adopting the practice. This paper examines the experiences of the Brazilian states that have implemented results agreements linked to variable pay. The analysis compares current with pre-intervention outcomes in the education, health, and security sectors. The changes are examined in relation to regional trends to determine whether the improvements depart in meaningful ways from the overall trend. In addition, a truncated time-series cross-section model is used to control for several additional factors influencing service delivery outcomes. The results suggest that, at least in the short and medium term, the implementation of results agreements is associated with significant and positive changes in outcomes in the security and education sectors. On average, states using team-level targets and performance-related pay have 15 fewer homicides per 100,000 inhabitants than those that do not, all else equal. Similarly, states that have introduced performance agreements and a bonus for teachers and school staff have improved their Basic Education Development Index score for public secondary schools by 0.3 additional points compared with the scores of states with similar characteristics. The conclusions are in line with the findings of in-depth impact evaluations and case study work in the education and security sectors (Bruns, Evans and Luque 2011, Milagres de Assis 2012). The paper does not analyze unit or team level data, which would be necessary to draw more rigorous conclusions about how results-based interventions affect the behavior of civil servants and outcomes over time. Therefore, the results should be interpreted with caution, as some of the assumptions behind the models cannot be examined with the available data.
Economic Conditions, Deterrence and Juvenile Crime: Evidence from Micro Data

This article investigates the determinants of criminal activity among juveniles in the United States. It uses a survey of U.S. high school students conducted in 1995, which provides detailed information on offenses; personal, family, and neighborhood characteristics; as well as deterrence measures. The determinants of selling drugs and committing assault, robbery, burglary, and theft are analyzed separately for males and females. The results provide some evidence that juveniles respond to incentives and sanctions. Employment opportunities and policies designed to increase the probability of arrest may be effective tools for reducing juvenile crime.
ScalaPipe: A Streaming Application Generator

ScalaPipe is a streaming application generator for heterogeneous platforms. By using a collection of domain-specific languages (DSLs) embedded in the Scala programming language, ScalaPipe allows creation of streaming applications that can run on a variety of hardware, including traditional processors, graphics processors, and field-programmable gate arrays (FPGAs). Its application DSL allows specification of the application topology and resource mapping. Its block DSL allows the authoring of implementations for processing kernels, or blocks, which are used in the streaming application. ScalaPipe makes it easy to generate, modify, and instrument large, complex topologies and resource mappings while also exposing optimization opportunities.
Effects of dissolved organic carbon and salinity on bioavailability of mercury

Hypotheses that dissolved organic carbon (DOC) and electrochemical charge affect the rate of methylmercury [CH3Hg(I)] synthesis by modulating the availability of ionic mercury [Hg(II)] to bacteria were tested by using a mer-lux bioindicator (O. Selifonova, R. Burlage, and T. Barkay, Appl. Environ. Microbiol. 59:3083-3090, 1993). A decline in Hg(II)-dependent light production was observed in the presence of increasing concentrations of DOC, and this decline was more pronounced at pH 7 than at pH 5, suggesting that DOC is a factor controlling the bioavailability of Hg(II). A thermodynamic model (MINTEQA2) was used to select assay conditions that clearly distinguished among various Hg(II) species. By using this approach, it was shown that negatively charged forms of mercuric chloride (HgCl3-/HgCl(4)2-) induced less light production than the electrochemically neutral form (HgCl2), and no difference was observed between the two neutral forms, HgCl2 and Hg(OH)2. These results suggest that the negative charge of Hg(II) species reduces their availability to bacteria and may be one reason why accumulation of CH3Hg(I) is more often reported to occur in freshwater than in estuarine and marine biota.
Measurement of the shear strength of a charge density wave.

We have explored the shear plasticity of charge density waves (CDWs) in NbSe3 samples with cross sections having a single microfabricated thickness step. Shear stresses along the step result from thickness-dependent CDW pinning. For small thickness differences the CDW depins elastically at the volume average depinning field. For large thickness differences the thicker, more weakly pinned side depins first via plastic shear, and shear plasticity contributes substantial dissipation well above the depinning field. A simple model describes the qualitative features of our data and yields a value for the CDW’s shear strength of approximately 9:5 � 10 3 Nm � 2 . This value is orders of magnitude smaller than the CDW’s longitudinal modulus but much larger than corresponding values for flux line lattices, and in part explains the relative coherence of the CDW response.
Successive monopolies and product variety

If there is a shift of market power from manufacturers to retailers or from retailers to manufacturers, how are consumers affected? When the value chain has successive firms, each with market power, the shifting balance of power up or down the chain (away from the consumer or towards the consumer, respectively) can lead to a further fractionation of the consumer market, meaning greater product variety. If retailers have a minimum efficient scale greater than manufacturers, a shift in bargaining power from manufacturers to retailers will increase consumer welfare while market fractionation can enhance firms' abilities to price discriminate, capturing some of this consumer surplus.
Dimension and rank for mapping class groups

We study the large scale geometry of the mapping class group, MCG(S). Our main result is that for any asymptotic cone of MCG(S), the maximal dimension of locally compact subsets coincides with the maximal rank of free abelian subgroups of MCG(S). An application is a proof of Brock-Farb’s Rank Conjecture which asserts that MCG(S) has quasi-flats of dimension N if and only if it has a rank N free abelian subgroup. (Hamenstadt has also given a proof of this conjecture, using different methods.) We also compute the maximum dimension of quasi-flats in Teichmuller space with the Weil-Petersson metric.
Informed Consent and the Capacity for Voluntarism

OBJECTIVE: Informed consent is built upon the elements of information, decisional capacity, and voluntarism. Of these elements, voluntarism in clinical and research consent is the least well understood. This has interfered with the ability to resolve key ethical problems faced by the field of psychiatry. METHOD: The author suggests that voluntarism encompasses an individual’s ability to act in accordance with one’s authentic sense of what is good, right, and best in light of one’s situation, values, and prior history. Voluntarism further entails the capacity to make this choice freely and in the absence of coercion. Deliberateness, purposefulness of intent, clarity, genuineness, and coherence with prior life decisions are implicitly emphasized in this construction. RESULTS: The author offers and illustrates a framework for voluntarism in clinical and research consent decisions, focusing on four domains of potential influence: 1) developmental factors, 2) illness-related considerations, 3) psychological is...
What Is Social Informatics and Why Does It Matter

Originally published in D-Lib Magazine, January, 1999. Available at http://www.dlib.org/dlib/january99/kling/01kling.html Reprinted with permission. A serviceable working conception of “social info...
Automorphisms of Generalized Thompson Groups

0.1. Results. We study the automorphisms of some generalizations of Thompson’s groups and their underlying structures. The automorphism groups of two of Thompson’s original groups were analyzed in [2] and were shown to be “small” and “unexotic.” Our results differ sharply from [2] in that we show that the automorphism groups of the generalizations are “large” and have “exotic” elements. The term exotic is from [1] and is explained later in this introduction. Richard J. Thompson introduced the triple of infinite groups F ⊆ T ⊆ G in the 1960s and showed that they have several interesting properties. These groups were later generalized to infinite groups Fn,∞ ⊆ Fn ⊆ Tn,r ⊆ Gn,r for n ≥ 2 and r ≥ 1 for which F = F2,∞ = F2, T = T2,1 and G = G2,1. Further background is given in the second part of this introduction. The automorphism groups Aut(F) and Aut(T) were analyzed in [2]. In this paper, we study Aut(Fn,∞), Aut(Fn) and Aut(Tn,n−1) for n > 2. We find that all three contain exotic elements, and that the complexity increases as n increases. We also find that the structures of Aut(Fn) and Aut(Tn,n−1) are closely related, while differing significantly from the structure of Aut(Fn,∞). This difference increases as n increases. Our analysis is only partial in that we discover large subgroups of these groups containing exotic elements, but we do not know whether the subgroups 1
A power control MAC protocol for ad hoc networks

This paper presents a power control MAC protocol that allows nodes to vary transmit power level on a per-packet basis. Several researchers have proposed simple modifications of IEEE 802.11 to incorporate power control. The main idea of these power control schemes is to use different power levels for RTS-CTS and DATA-ACK. Specifically, maximum transmit power is used for RTS-CTS, and the minimum required transmit power is used for DATA-ACK transmissions in order to save energy. However, we show that these schemes can degrade network throughput and can result in higher energy consumption than when using IEEE 802.11 without power control. We propose a power control protocol which does not degrade throughput and yields energy saving.
Regulated Emissions, Air Toxics, and Particle Emissions from SI-DI Light-Duty Vehicles Operating on Different Iso-Butanol and Ethanol Blends

Gasoline direct injection (GDI) engines have improved thermodynamic efficiency (and thus lower fuel consumption) and power output compared with port fuel injection (PFI) and their penetration is expected to rapidly grow in the near future in the U.S. market. In addition, the use of alternative fuels is expanding, with a potential increase in ethanol content beyond the current 10%. Increased emphasis has been placed on butanol due to its more favorable fuel properties, as well as new developments in production processes. This study explores the influence of mid-level ethanol and iso-butanol blends on criteria emissions, gaseous air toxics, and particulate emissions from two wall-guided gasoline direct injection passenger cars fitted with three-way catalysts. Emission measurements were conducted over the Federal Test Procedure (FTP) driving cycle on a chassis dynamometer. This study utilized seven fuels with varying ethanol and iso-butanol contents, including E10, E15, E20, Bu16, Bu24, Bu32, and a mixture of E20 and Bu16 resulting in E10/Bu8. Emissions included nitrogen oxides (NO x ), carbon monoxide (CO), total hydrocarbons (THC), non-methane hydrocarbons (NMHC), methane (CH 4 ), and carbon dioxide (CO 2 ). Additionally, carbonyl compounds, 1,3-butadiene, benzene, ethylbenzene, toluene, and xylenes were quantified in the exhaust. Total particle number emissions, black carbon, and real-time particle size distributions were also measured. The results are discussed in the context of the changing fuel type and composition.
Oblivious bounds on the probability of boolean functions

This article develops upper and lower bounds for the probability of Boolean functions by treating multiple occurrences of variables as independent and assigning them new individual probabilities. We call this approach dissociation and give an exact characterization of optimal oblivious bounds, that is, when the new probabilities are chosen independently of the probabilities of all other variables. Our motivation comes from the weighted model counting problem (or, equivalently, the problem of computing the probability of a Boolean function), which is nP-hard in general. By performing several dissociations, one can transform a Boolean formula whose probability is difficult to compute into one whose probability is easy to compute, and which is guaranteed to provide an upper or lower bound on the probability of the original formula by choosing appropriate probabilities for the dissociated variables. Our new bounds shed light on the connection between previous relaxation-based and model-based approximations and unify them as concrete choices in a larger design space. We also show how our theory allows a standard relational database management system (DBMS) to both upper and lower bound hard probabilistic queries in guaranteed polynomial time.
Optimal joining of compacted cells

Three algorithms to join two compacted cells by using a combination of stretching and river routing are developed. Each of these obtains the minimum area joining. One algorithm obtains a minimum area joining that also minimizes the length of the longest wire. Another obtains a minimum area joining that has the least possible total wire length. The simplest of the algorithms guarantees only a minimum are joining. All algorithms have a low-order polynomial complexity. Experimental results indicate that the algorithms obtain joinings that are significantly superior to those obtained using the heuristic of G. Cheng and A. Despain (1989). >
Optimal distributed online prediction using mini-batches

Online prediction methods are typically presented as serial algorithms running on a single processor. However, in the age of web-scale prediction problems, it is increasingly common to encounter situations where a single processor cannot keep up with the high rate at which inputs arrive. In this work, we present the distributed mini-batch algorithm, a method of converting many serial gradient-based online prediction algorithms into distributed algorithms. We prove a regret bound for this method that is asymptotically optimal for smooth convex loss functions and stochastic inputs. Moreover, our analysis explicitly takes into account communication latencies between nodes in the distributed environment. We show how our method can be used to solve the closely-related distributed stochastic optimization problem, achieving an asymptotically linear speed-up over multiple processors. Finally, we demonstrate the merits of our approach on a web-scale online prediction problem.
Bayes Estimators for Phylogenetic Reconstruction

Tree reconstruction methods are often judged by their accuracy, measured by how close they get to the true tree. Yet, most reconstruction methods like maximum likelihood (ML) do not explicitly maximize this accuracy. To address this problem, we propose a Bayesian solution. Given tree samples, we propose finding the tree estimate that is closest on average to the samples. This “median” tree is known as the Bayes estimator (BE). The BE literally maximizes posterior expected accuracy, measured in terms of closeness (distance) to the true tree. We discuss a unified framework of BE trees, focusing especially on tree distances that are expressible as squared euclidean distances. Notable examples include Robinson–Foulds (RF) distance, quartet distance, and squared path difference. Using both simulated and real data, we show that BEs can be estimated in practice by hill-climbing. In our simulation, we find that BEs tend to be closer to the true tree, compared with ML and neighbor joining. In particular, the BE under squared path difference tends to perform well in terms of both path difference and RF distances.
Elastic and inelastic line-soliton solutions of the Kadomtsev-Petviashvili II equation

The Kadomtsev-Petviashvili II (KPII) equation admits a large variety of multi-soliton solutions which exhibit both elastic as well as inelastic types of interactions. This work investigates a general class of multi-solitons which were not previously studied, and which do not in general conserve the number of line solitons after interaction. The incoming and outgoing line solitons for these solutions are explicitly characterized by analyzing the @t-function generating such solutions. A special family of N-soliton solutions is also considered in this article. These solutions are characterized by elastic soliton interactions, in the sense that amplitude and directions of the individual line solitons as y->~ are the same as those of the individual line solitons as y->-~. It is shown that the solution space of these elastic N-soliton solutions can be classified into (2N-1)!! disjoint sectors which are characterized in terms of the amplitudes and directions of the N line solitons.
Paying the price for unreliable power supplies : in-house generation of electricity by firms in Africa

This paper documents the prevalence of in-house generation of electric power by firms in Sub-Saharan Africa and attempts to identify the underlying causes. The analysis is based on two data sources. The UDI World Electric Power Plants Data Base (WEPP), a global inventory of electric power generating units, provides a detailed inventory of in-house generation at the country level. The World Bank's Enterprise Survey Database captures business perceptions of the obstacles to enterprise growth for 8,483 currently operating firms in 25 African countries. Overall, so-called own generation by firms-which has been on the rise in recent years-accounts for about 6 percent of installed generation capacity in Sub-Saharan Africa (equivalent to at least 4,000 MW of installed capacity). However, this share doubles to around 12 percent in the low-income countries, the post-conflict countries, and more generally on the Western side of the continent. In a handful of countries own generation represents more than 20 percent of capacity. Rigorous empirical analysis shows that unreliable public power supplies is far from being the only or even the largest factor driving generator ownership. Firm characteristics have a major influence-in particular, the probability of owning a generator doubles in large firms relative to small ones. Our model predicts that the prevalence of own generation would remain high (at around 20 percent) even if power supplies were perfectly reliable, suggesting that other factors, such as emergency back-up and export regulations, play a critical role in the decision to own a generator.
A highly regio- and stereoselective transition metal-catalyzed hydrosilylation of terminal alkynes under ambient conditions of air, water, and room temperature

A highly efficient and stereoselective hydrosilylation of terminal alkynes was developed at room temperature in air and water.
Meeting an 80% Reduction in Greenhouse Gas Emissions from Transportation by 2050: A Case Study in California

This paper investigates how California may reduce transportation greenhouse gas emissions 80% below 1990 levels by 2050 (i.e., 80in50). A Kaya framework that decomposes greenhouse gas emissions into the product of population, transport intensity, energy intensity, and carbon intensity is used to analyze emissions and mitigation options. Each transportation subsector, including light-duty, heavy-duty, aviation, rail, marine, agriculture, and off-road vehicles, is analyzed to identify specific mitigation options and understand its potential for reducing greenhouse gas emissions. Scenario analysis shows that, while California’s 2050 target is ambitious, it can be achieved in transport if a concerted effort is made to change travel behavior and the vehicles and fuels that provide mobility. While no individual ‘‘Silver Bullet” strategy exists that can achieve the goals, a portfolio approach that combines strategies could yield success. The 80in50 scenarios show the impacts of advanced vehicle and fuels technologies as well as the role of travel demand reduction, which can significantly reduce energy and resource requirements and the level of technology development needed to meet the target.
Political Restraint of the Market and Levels of Criminal Homicide: A Cross-National Application of Institutional-Anomie Theory

This article examines the effects on national homicide rates of political efforts to insulate personal well-being from market forces. Drawing upon recent work by EspingAndersen and the institutional-anomie theory of crime, we hypothesize that levels of homicide will vary inversely with the "decommodification of labor." We develop a measure of decommodification based on levels and patterns of welfare expenditures and include this measure in a multivariate, cross-national analysis of homicide rates. The results support our hypothesis and lend credibility to the institutional-anomie perspective. The degree of decommodification is negatively related to homicide rates, net of controls for other characteristics of nations. Interest in explaining differences among nations in rates of crime and violence is as old as the sociology of crime itself. The quantitative measurement of these differences by the nineteenth-century moral statisticians Quetelet and Guerry marks the beginning of scientific criminological inquiry (Beirne 1993). Marx also refers to national crime data in the course of developing his critique of the inherent flaws of capitalism. "There must be something rotten in the very core of a social system," Marx (1859) writes, "which increases its wealth without diminishing its misery, and increases in crimes even more rapidly
ecp: An R Package for Nonparametric Multiple Change Point Analysis of Multivariate Data

There are many different ways in which change point analysis can be performed, from purely parametric methods to those that are distribution free. The ecp package is designed to perform multiple change point analysis while making as few assumptions as possible. While many other change point methods are applicable only for univariate data, this R package is suitable for both univariate and multivariate observations. Hierarchical estimation can be based upon either a divisive or agglomerative algorithm. Divisive estimation sequentially identifies change points via a bisection algorithm. The agglomerative algorithm estimates change point locations by determining an optimal segmentation. Both approaches are able to detect any type of distributional change within the data. This provides an advantage over many existing change point algorithms which are only able to detect changes within the marginal distributions.
Generalized Noncrossing Partitions and Combinatorics of Coxeter Groups

Introduction Coxeter groups and noncrossing partitions $k$-divisible noncrossing partitions The classical types Fuss-Catalan combinatorics Bibliography.
Integrating Unions in Integrated Conflict Management Systems

Can integrated conflict management systems (ICMSs) be fully and successfully integrated in unionized workplaces? This article proposes best-practice guidelines based on new field research. It argues that integration is possible and beneficial for unions and organizations, but that certain considerations must be addressed to ensure that ICMSs complement and support unions’ roles in the workplace rather than act as substitutes. When ICMSs are introduced and maintained collaboratively in a way that engages unions as key co-owners of such systems, the article suggests they can ultimately be made more effective and resilient than when implemented in nonunion settings.
Testing of zipper CMOS logic circuits

Zipper CMOS is a dynamic CMOS circuit technique which also provides protection against instability and charge-sharing problems; this is achieved by using a special driver circuit. A method for testing of zipper CMOS circuits is presented. The testing is done with the help of a single stuck-at-fault test set derived from the gate-level model of the circuit in which the vectors have to be properly arranged and sometimes also repeated. This test set detects not just all detectable stuck-at faults but stuck-open and stuck-on faults as well. Very few stuck-open faults require two-pattern tests, and very few stuck-on faults need current monitoring. Thus, zipper CMOS circuits in particular and dynamic CMOS circuits in general enjoy a huge testability advantage over static CMOS circuits. Faults in the driver circuit are also considered. >
How Minerals React with Water

Reactions between mineral surfaces and water play an important role in dissolution, precipitation, and sorption processes, thereby affecting a wide range of natural and technological processes. In his Perspective, Brown charts recent progress toward understanding these complex interfacial processes. Progress has been greatly aided by new techniques that allow atomic-scale characterization under reactive conditions. Many aspects of mineral surface reactivity have been elucidated, but many aspects of the structure and properties of water near the interface remain uncertain.
Well-Defined Silica-Supported Olefin Metathesis Catalysts

Two triethoxysilyl-functionalized N-heterocyclic carbene ligands have been synthesized and used to prepare the corresponding second-generation ruthenium olefin metathesis catalysts. These complexes were then grafted onto silica gel, and the resulting materials were efficient heterogeneous catalysts for a number of metathesis reactions. The solid-supported catalysts were shown to be recyclable over a number of reaction cycles, and no detectable levels of ruthenium were observed in reaction filtrates (ruthenium concentration of filtrate <5 ppb).
A general method for the synthesis of 1,1-difluoroalkylphosphonates

Abstract A facile method for preparing 1,1-difluoroalkylphosphonates has been developed that features radical deoxygenation of thionocarbonates derived from the adducts formed upon addition of 9 to aldehydes.
Scope and Limitations of Pd2(dba)3/P(i-BuNCH2CH2)3N-Catalyzed Buchwald−Hartwig Amination Reactions of Aryl Chlorides

Proazaphosphatrane ligands in combination with Pd2(dba)3 generate highly active catalysts for Buchwald−Hartwig amination of aryl chlorides. In particular, commercially available P(i-BuNCH2CH2)3N is a highly general and efficient ligand, allowing the coupling of an electronically diverse set of aryl chlorides, including chloropyridines, with a wide variety of amines using 1 mol % of Pd at 100 °C. Either a 1:1 or 2:1 ratio of ligand to Pd was found to be effective. This catalyst system performs exceptionally well for sterically hindered substrates, even with only 0.25 mol % of Pd. It is shown that NaOH can also be used as the base (instead of NaO-t-Bu) allowing functionalized substrates to participate in these reactions.
On the possibility of Casimir repulsion using Metamaterials

It is well known that the Casimir force between two half-spaces is dictated by their electromagnetic properties. In particular, when one of the half-spaces is mainly metallic or dielectric and the other is mainly magnetic, it is possible to show that the force is repulsive. This has attracted lots of interest towards the study of metamterials (MMs) in the context of Casimir effect, as their magnetic activity might help bring the idea of Casimir repulsion from the theoretical realm to experimental verification. In this paper we investigate the possibility of repulsion when the MM magnetic permeability is given not by a Drude-Lorentz behavior, but by a model put forward by Pendry et al. [16]. After introducing the model and deriving the necessary formulas, we show that it is impossible to achieve repulsion with such a model and present a qualitative discussion of why this is so.
Why Democracies Cooperate More and Fight Less: The Relationship Between International Trade and Cooperation

This paper provides an economics-based interpretation of the standard finding in the literature that democracies rarely fight each other. A general theory of conflict between two countries is presented and empirical analysis applies this theory to the question of why democracies rarely fight each other. The results show that the fundamental factor in causing bilateral cooperation is trade. Countries seek to protect wealth gained through international trade, therefore trading partners are less combative than nontrading nations. Democratic dyads trade more than nondemocratic dyads, and thus exhibit less conflict and more cooperation.
Attitude Sensing Using a Global-Positioning-System Antenna on a Turntable

A new attitude sensor is proposed that consists of a single global positioning system (GPS) antenna mounted on a turntable with its phase center offset from the turntable's spin axis. It is being considered as a means of sensing 3-axis attitude information. It is attractive because its GPS receiver could have a low number of channels and, therefore, be smaller and use less power. The system senses attitude by demodulation of periodic oscillations of the GPS carrier phase. These oscillations are caused by the turntable’s rotation, and their amplitude and phase depend on the direction vector to the tracked GPS satellite. This system is described in detail, its demodulation phase-locked loop is designed, and its performance is analyzed and evaluated via simulation. The computer simulation results show that, when using a turntable radius of 0.1 m, a rotation rate of 4,000 RPM, and an ovenized crystal oscillator for the receiver clock, the system can sense vector attitude with a 1-σ accuracy of 1.4 deg at a bandwidth of 0.64 Hz. Accuracy can be improved by increasing the turntable radius or by reducing multi-path reflections.
Weighted optimization for multiobjective full-information control problems

We consider a nonlinear multiobjective full-information optimal control problem, where a controller is to be designed such that a number of constraints are to be satisfied for all possible disturbances. We show that, under certain continuity assumptions, such a controller exists if and only if, for every weighted combination of the constraints, there exists a controller satisfying the weighted constraint. Our analysis is based extensively on nonlinear H/sub /spl infin// dynamic programming methods.
Delay predictors for customer service systems with time-varying parameters

Motivated by interest in making delay announcements in service systems, we develop new real-time delay predictors that effectively cope with customer abandonment and time-varying parameters. First, we focus on delay predictors exploiting recent customer delay history. We show that time-varying arrival rates can introduce significant prediction bias in delay-history-based predictors when the system experiences alternating periods of overload and underload. We then introduce a new delay-history-based predictor that effectively copes with time-varying arrival rates. Second, we consider a time-varying number of servers. We develop two new predictors which exploit an established deterministic fluid approximation for a many-server queueing model with time-varying demand and capacity. The new predictors effectively cope with those features, often observed in practice. Throughout, we use computer simulation to quantify the performance of the alternative delay predictors.
Boundary filters for finite-length signals and time-varying filter banks

We examine the question of how to construct time-varying filter banks in the most general M-channel nonorthogonal case. We show that by associating with both analysis and synthesis operators a set of boundary filters, it is possible to make the analysis structure vary arbitrarily in time, and yet reconstruct the input with a similarly time-varying synthesis section. There is no redundancy or distortion introduced. This gives a solution to the problem of applying filter banks to finite length signals; it suffices to apply the boundary filters at the beginning and end of the signal segment. This also allows the construction of orthogonal and nonorthogonal bases with essentially any prescribed time and frequency localization, but which, nonetheless, are based on structures with efficient filter bank implementations. >
Transcriptional Regulation and Its Misregulation in Disease

The gene expression programs that establish and maintain specific cell states in humans are controlled by thousands of transcription factors, cofactors, and chromatin regulators. Misregulation of these gene expression programs can cause a broad range of diseases. Here, we review recent advances in our understanding of transcriptional regulation and discuss how these have provided new insights into transcriptional misregulation in disease.
Axial-Selective Prins Cyclizations by Solvolysis of α-Bromo Ethers

Prins cyclizations are intramolecular electrophilic additions of oxocarbenium ions. They lead to tetrahydropyrans with a heteroatom at the 4-position, and usually show moderate-to-high selectivity for equatorial substitution. We have found that Prins cyclizations carried out under specific conditions produce tetrahydropyrans with almost exclusive formation of the axial 4-substituent. TMSBr, AcBr, and TMSI all lead to axial-selective Prins cyclizations with α-acetoxy ether substrates in the presence lutidine. The mechanism appears to involve solvolysis of the intermediate α-bromo ether rather than specific or Lewis acid-catalyzed rearrangement. The scope of the reaction, the high yields, and the stereoselectivity make this a valuable new method for tetrahydropyran formation.
Enhanced sensitivity of persistent events to weak forcing in dynamical and stochastic systems: Implications for climate change

Low-dimensional models can give insight into the climate system, in particular its response to externally imposed forcing such as the anthropogenic emission of green-house gases. Here, we use the Lorenz system, a chaotic dynamical system characterized by two “regimes”, to examine the effect of a weak imposed forcing. We show that the probability density functions (PDF's) of time-spent in the two regimes are exponential, and that the most dramatic response to forcing is a change in the frequency of occurrence of extremely persistent events, rather than the weaker change in the mean persistence time. This enhanced sensitivity of the “tails” of the PDF's to forcing is quantitatively explained by changes in the stability of the regimes. We demonstrate similar behavior in a stochastically forced double well system. Our results suggest that the most significant effect of anthropogenic forcing may be to change the frequency of occurrence of persistent climate events, such as droughts, rather than the mean.
Improving the Accessibility of the NBER's Historical Data

During its early years, the National Bureau of Economic Research (NBER) assembled an extensive dataset on the pre-World War II economy. In 1978, the Inter-University Consortium for Political and Social Research transferred the data from the NBER's handwritten sheets to a machine-readable format. Modern econometric software cannot easily read this format, however, and the data-keying process produced several errors. We have converted the machine-readable dataset to a portable format and verified its accuracy using the NBER's handwritten sheets. The dataset is now available on the Internet and can be accessed using standard gopher or web-browser software.
On the expressibility of stable logic programming

Schlipf (1995) proved that Stable Logic Programming (SLP) solves all $\mathit{NP}$ decision problems. We extend Schlipf's result to prove that SLP solves all search problems in the class $\mathit{NP}$. Moreover, we do this in a uniform way as defined in Marek and Truszczynski (1991). Specifically, we show that there is a single $\mathrm{DATALOG}^{\neg}$ program $P_{\mathit{Trg}}$ such that given any Turing machine $M$, any polynomial $p$ with non-negative integer coefficients and any input $\sigma$ of size $n$ over a fixed alphabet $\Sigma$, there is an extensional database $\mathit{edb}_{M,p,\sigma}$ such that there is a one-to-one correspondence between the stable models of $\mathit{edb}_{M,p,\sigma} \cup P_{\mathit{Trg}}$ and the accepting computations of the machine $M$ that reach the final state in at most $p(n)$ steps. Moreover, $\mathit{edb}_{M,p,\sigma}$ can be computed in polynomial time from $p$, $\sigma$ and the description of $M$ and the decoding of such accepting computations from its corresponding stable model of $\mathit{edb}_{M,p,\sigma} \cup P_{\mathit{Trg}}$ can be computed in linear time. A similar statement holds for Default Logic with respect to $\Sigma_2^\mathrm{P}$-search problems.
Contributions to Seymour's second neighborhood conjecture

Let D be a simple digraph without loops or digons. For anyv2 V.D/ let N1.v/ be the set of all nodes at out-distance 1 from v and let N2.v/ be the set of all nodes at out-distance 2. We show that if the underlying graph is triangle-free, there must exist somev2 V.D/ such thatjN1.v/jj N2.v/j. We provide several properties a “minimal” graph which does not contain such a node must have. Moreover, we show that if one such graph exists, then there exist infinitely many.
Novel purine-based fluoroaryl-1,2,3-triazoles as neuroprotecting agents: Synthesis, neuronal cell culture investigations, and CDK5 docking studies

A series of novel purine-based fluoroaryl triazoles were synthesized using the Cu(I) catalyzed 1,3-dipolar cycloaddition reactions (click reactions), and assayed for their neuroprotective effects using fluorescence electron microscopy. Among these triazoles, o-fluorophenylmetyl-triazole, 7, has comparable neuroprotective effect as that of Flavopiridol (1) and Roscovitine (2), the state of the art CDK inhibitors, against the Aβ induced neurotoxicity. These results are substantiated using computer docking methods (DarwinDock/GenDock), which predict that Roscovitine and the triazole 7 bind to the ATP-binding site of CDK5/p25 with comparable binding energies, whereas the corresponding pentafluorophenylmethyl-triazole, 9, has dramatically reduced binding energy (in accordance with its lack of neuroprotection). These combined experimental and theoretical studies support the involvement of CDK5/p25 in the neuronal cell cycle re-entry.
Demonstration of temporal cloaking

We present the first experimental demonstration of cloaking an event in the time domain. Our temporal cloaking scheme is based on the time-space duality and the use of novel split time-lenses.
Perspectives on Parsimony: How Long Is the Coast of England? A Reply to Park and MacInnis; Schwarz; Petty; and Lynch

Park and MacInnis (2006, in this issue) provide the always sound advice to examine the boundaries of the focal construct, in this case attitudes. They wonder whether attitudes are capable of predicting differences in levels of personal investment and commitment to resulting behavior, and they question whether attitude dimensions such as strength and extremity, or additional dimensions and moderators, are rich enough to account for either the range of affect intensity reflected in the degree of emotional attachment or in behavioral commitment. They draw our attention to consumers’ emotional attachment to brands (which they see as inherently linked to one’s self-schema) and argue for a sharper delineation of the boundaries of the attitude construct. Their analysis suggests that emotional attachment is a separate relationship-based construct. Several reactions seem in order. First, we do not suggest that attitude theory can explain emotional attachment and its consequences (see also Cohen [1990], Cohen and Areni [1991], and Pham et al. [2001] for consistent attempts to separate attitudinal and affective processes). In creating the Multiple Pathway Anchoring and Adjustment (MPAA) model, we draw on relevant cognitive and motivational theory and research to better understand both attitude formation and the conditions under which attitudes are likely to guide behavior. Attitudes arise out of a range of human experience extending from direct experience and exposure to internal*Cohen and Reed’s (2006, in this issue) MPAA model describes the attitude formation and reliance process. We thank the notable contributors for their insightful commentaries about our model and attitude theory and research more generally. Since we cannot respond to all the nuances outlined in each of the four separate articles, we primarily address some important differences in the commentators’ views about parsimony. The spirit of our response is intended to convince readers that when it comes to representing psychological processes, there is no one right model. Rather, the construct mapping one uses and related judgments about parsimony should depend on explicit research goals. Joel B. Cohen is Distinguished
The Effects of Space Radiation on Mosfet Devices and Some Application Implications of Those Effects

MOSFET devices and microcircuits have been designed and built into flight hardware for use in open operational spacecraft (IMP D&E) by NASA/GSFC. A look at some of the engineering results associated with studying this class of devices for use in these applications is reviewed here. In addition, there is a first-cut engineering study for comparison of performance, in a simulated space radiation environment, of two types of MOSFET's and the newer experimental silicon nitrite devices (MNS-FET). The experiments reported upon are application parameter oriented and of limited sample size. Therefore, no attempt is made to draw any far-reaching conclusions about MOSFET's in general, nor are any devices physics oriented interpretations included.
Orbifolds and solitons

Abstract We propose a conformal field theory description of a solitonic heterotic string in type IIA superstring theory compactified on K 3, generalizing previous work by J. Harvey, A. Strominger and A. Sen. In ten dimensions the construction gives a fivebrane which is related to the fundamental type II string by electric-magnetic duality, and to the Dirichlet fivebrane of type IIB string theory by SL (2, Z ).
What is a Peer? The Role of Network Definitions in Estimation of Endogenous Peer Effects

We employ a standard identification strategy from the peer effects literature to investigate the importance of network definitions in estimation of endogenous peer effects. We use detailed information on friends in the National Longitudinal Study of Adolescent Health Survey (Add Health) to construct two network definitions that are less ad hoc than the school-grade cohorts commonly used in the educational peer effects literature. We demonstrate that accurate definitions of the network seriously impact estimation of peer effects. In particular, we show that peer effects estimates on educational achievement, smoking and drinking are substantially larger with our more detailed measures than with the school-grade cohorts. These results highlight the need to further understand how friendships form in order to fully understand implications for policy that alters the peer group mix at the classroom or cohort level.
Choice and Procrastination

Author(s): O'Donoghue, Ted; Rabin, Matthew | Abstract: Recent models of procrastination due to self-control problems assume that a procrastinator considers just one option and is unaware of her self-control problems. We develop a model where a person chooses from a menu of options and is partially aware of her self-control problems. This menu model replicates earlier results and generates new ones. A person might forego completing an attractive option because she plans to complete a more attractive but never-to-be-completed option. Hence, providing a non-procrastinator additional options can induce procrastination, and a person may procrastinate worse pursuing important goals than unimportant ones.
Spatio-temporal modeling of wireless users internet access patterns using self-organizing maps

Users behavior and interests will play a central role in future mobile networks. We introduce a systematic method for large-scale multi-dimensional analysis of online activity for thousands of mobile users across 79 buildings over 100 web domains. We propose a modeling approach based on self-organizing maps for discovering, organizing and visualizing different mobile users' trends from billions of WLAN and netflow records. We find surprisingly that users' trends based on domains or locations can be modeled using a self-organizing map with clearly distinct characteristics. This is the first study to acquire such detailed results for wireless users Internet access patterns.