cssi/SciSciGPT-SciSciNet huggingface dataset:
Introduction to M theory and AdS/CFT duality

An introductory survey of some of the developments that have taken place in superstring theory in the past few years is presented. The main focus is on three particular dualities. The first one is the appearance of an 11th dimension in the strong coupling limit of the type IIA theory, which give rise to M theory. The second one is the duality between the type IIB theory compactified on a circle and M theory on a two-torus. The final topic is an introduction to the recently proposed duality between superstring theory or M theory on certain anti de Sitter space backgrounds and conformally invariant quantum field theories.
Is better information always good news ? international corporate strategy and regulation

This paper develops a simple model to analyze the interaction between strategic corporate public good provision, international firm location and national regulation. An information-based strategic corporate public good provision mechanism is proposed to shed light on recent firm behavior within different regulatory environments. The main insight derived is that in the presence of firms with geographic flexibility (multinational enterprises) and market provision of an international public credence good, unilateral (non-cooperative) regulatory scope depends on (1) the absolute probabilities to verify firms' corporate public good provision levels within different geographic and institutional environments, and (2) the differential between these probabilities across countries. The relative information asymmetry determines not only the market levels of the public good produced under autarky, but also the relocation incentives of multinational enterprises. A firm trades off lower production costs, which increase its competitiveness in pricing, with higher expected informational price premiums, which decrease its competitiveness. A government's ability to regulate above market (corporate public good provision) levels decreases with the absolute level of foreign transparency, while it increases in the relative (positive) difference between the same transparency at home and abroad. This may not only explain mixed empirical evidence of theoretic propositions such as the Pollution Haven Hypothesis and Regulatory Race to the Bottom dynamics, but also open up interesting policy implications as the international information playing field becomes leveled through development, while existing regulations are rather rigid, and policy coordination remains limited.
Context-Bounded model checking of concurrent software

The interaction among concurrently executing threads of a program results in insidious programming errors that are difficult to reproduce and fix. Unfortunately, the problem of verifying a concurrent boolean program is undecidable [24]. In this paper, we prove that the problem is decidable, even in the presence of unbounded parallelism, if the analysis is restricted to executions in which the number of context switches is bounded by an arbitrary constant. Restricting the analysis to executions with a bounded number of context switches is unsound. However, the analysis can still discover intricate bugs and is sound up to the bound since within each context, a thread is fully explored for unbounded stack depth. We present an analysis of a real concurrent system by the ZING model checker which demonstrates that the ability to model check with arbitrary but fixed context bound in the presence of unbounded parallelism is valuable in practice. Implementing context-bounded model checking in ZING is left for future work.
Legitimacy and Corporate Law: The Case for Regulatory Redundancy

This Article provides a democratic assessment of the corporate lawmaking structure in the United States. It draws upon the basic democratic principle that those affected by legal rules should have a voice in determining the substance of those rules. Although other commentators have noted certain undemocratic aspects of corporate law, this Article aims to present a more comprehensive assessment of the corporate regulatory regime. It departs from prior accounts by looking past the states’ role to consider the ways that federal regulation shores up the legitimacy of the overarching structure. This focus on the federal role provides some comfort on a democratic account, but also counsels caution with respect to continuing efforts to limit the scope of the federal role within the corporate governance structure. At the federal level, Congress has chosen to regulate corporate matters by setting broad policy objectives and delegating administrative tasks to the Securities and Exchange Commission (SEC). The democratic legitimacy of the corporate regulatory regime thus requires proper respect for the discretion that Congress has vested in the agency.  Associate Professor, Boston College Law School, A.B., Princeton, J.D., Harvard. The author thanks Joan Blum, Lawrence Cunningham, Elizabeth Foote, John Gordon, Ray Madoff, Michael McCann and Vlad Perju for helpful comments on drafts of this Article. The Article also benefited from comments by participants at the panel on Firms, Markets and Social Welfare at the 2008 Annual Meeting of the Law and Society Association and at a Boston College Law School Faculty Workshop. Joanne Ricciardiello and Arianna Tunsky provided excellent research assistance. Research support was generously provided by the Perini Family Faculty Research Fund. 1274 WASHINGTON UNIVERSITY LAW REVIEW [VOL. 86:1273 This Article therefore urges skepticism toward efforts to constrain the SEC’s regulatory role through judicial challenges to its rulemaking authority. It argues that the agency’s ability to respond deftly to market crises and scandals has been hampered unnecessarily by a tradition of aggressive judicial review of agency rulemaking. While rooted in concerns for preserving democratic accountability, this tradition has undermined the very values it seeks to protect. Because the procedures for SEC rulemaking comport well with democratic principles, the agency deserves more deference than courts have been willing to allow. The analysis has implications for current proposals to reform regulation of the national financial markets. Calls to reduce or weaken the SEC’s role in financial regulation should give pause to those concerned with the democratic integrity of our regulatory processes. It is the SEC’s political independence that bolsters its ability to navigate the rough terrain of regulating the powerful industries within its jurisdiction. Enhancing rather than diminishing the agency’s independence should be a central element of proposals to reform our financial regulatory system.
Adaptive web processes using value of changed information

Web process composition is receiving much attention as an important problem for the services oriented computing community. Most compositions built by planning methods use a pre-defined model of the process environment. These methods have assumed that the information in the models and consequently the compositions remain static and accurate throughout the life cycle of the Web process. We describe an approach that accounts for the dynamic nature of services by formulating a system that queries external sources intelligently. We give a method for measuring the value of change that revised information may potentially introduce in the Web process. We provide an algorithm that calculates and uses this value to optimally adapt the Web process to possible changes in the environment. Using two realistic scenarios, we show our idea and compare its performance to alternative approaches.
Trade Costs, Barriers to Entry, and Export Diversification in Developing Countries

This paper finds that a 1 percent reduction in the cost of exporting or the cost of international transport is associated with an export diversification gain of 0.3 percent or 0.4 percent respectively. Lower domestic market entry costs can also promote diversification, but the elasticity is weaker (-0.1). To obtain these results, the authors construct new measures of export diversification for 118 developing countries using highly detailed 8-digit mirror data from the European Union. The analysis also incorporates new export cost data from the World Bank's Doing Business database, covering document preparation, inland transport, administrative fees, and port/customs charges. Findings are highly robust, including to the use of geography and colonial history as instruments for trade and entry costs. Both the signs and relative magnitudes of these effects are consistent with predictions from a heterogeneous firms model of trade with asymmetric costs.
Nucleon electromagnetic form-factors

The nucleon electromagnetic form factors have been studied in the past extensively from unpolarized electron scattering experiments. With the development in polarized beam, recoil polarimetry, and polarized target technologies, polarization experiments have provided more precise data on these quantities. In this talk, I review recent experimental progress on this subject.
A framework for schema-driven relationship discovery from unstructured text

We address the issue of extracting implicit and explicit relationships between entities in biomedical text. We argue that entities seldom occur in text in their simple form and that relationships in text relate the modified, complex forms of entities with each other. We present a rule-based method for (1) extraction of such complex entities and (2) relationships between them and (3) the conversion of such relationships into RDF. Furthermore, we present results that clearly demonstrate the utility of the generated RDF in discovering knowledge from text corpora by means of locating paths composed of the extracted relationships.
Timed-Release Cryptography

Let n be a large composite number. Without factoring n, the computation of a2t (mod n) given a, t with gcd(a, n) = 1 and t < n can be done in t squarings modulo n. For t ≪ n (e.g., n ≥ 21024 and t < 2100), no lower complexity than t squarings is known to fulfill this task. Rivest et al suggested to use such constructions as good candidates for realising timed-release crypto problems. We argue the necessity for a zero-knowledge proof of the correctness of such constructions and propose the first practically efficient protocol for a realisation. Our protocol proves, in log2 t standard crypto operations, the correctness of (ae)2t (mod n) with respect to ae where e is an RSA encryption exponent. With such a proof, a Timed-release Encryption of a message M can be given as a2t M (mod n) with the assertion that the correct decryption of the RSA ciphertext Me (mod n) can be obtained by performing t squarings modulo n starting from a. Timed-release RSA signatures can be constructed analogously.
Unified index for mobile object data and authorizations

Often, enforcing security incurs overhead, and as a result may degrade the performance of a system. In this paper, we attempt to address this problem in the context of enforcing access control policies in a mobile data object environment. There are a number of applications that call for fine-grained specification of security policies in guaranteeing the confidentiality of data or privacy of individuals in a mobile environment. In particular, the security policies state the rules for providing controlled access to the mobile user profiles, to their current location and movement trajectories, to mobile resources, and stationary resources based on the mobile user location. Either a subject or an object in an authorization specification can be a moving object. The access requests in such an environment can typically be based on past, present and future status of the moving objects. To effectively serve such access requests, one must efficiently organize the mobile objects as well as authorizations. Although implementation of authorizations as access control list, capability list or access matrix is suitable for traditional data, it is not suitable to search mobile object authorizations as they are based on spatial and temporal attributes of subjects and objects, rather than subject and object identifiers. When a subject issues an access request, the system must first retrieve the relevant objects from the moving object database, and then verify whether there exists an authorization that allows the subject to access these objects. Since both the moving objects and authorizations are spatiotemporal in nature, for efficient processing of access requests, it is essential that they both be organized using some index structures. As a result, processing an access request requires searching two indexes – one, the moving object index, and the other, the authorization index. To improve the response time of access requests, in this paper, we propose a unified index structure, called STPR-tree to index both moving objects and authorizations that govern access to them. As a result of the unified index, access requests can be processed in one pass, thereby improving the response time. Note that current access control systems do not use any index for authorizations; our work is a step in this direction. We show how the STPR-tree can be constructed and maintained, and provide algorithms to process access requests.
The effects of land registration on financial development and economic growth - a theoretical and conceptual framework

The author develops a theoretical framework to guide empirical analysis of how land registration affects financial development and economic growth. Most conceptual approaches investigate the effects of land registration on only one sector, nut land registration is commonly observed to affect not only other sectors but the economy as a whole. The author builds on the well-tested link between secure land ownership and farm productivity, adding to the framework theory about positive information and transaction costs. To map the relationship between land registration and financial development and economic growth, the framework links: 1) Land tenure security and investment incentives. 2) Land title, collateral, and credit. 3) Land markets, transactions, and efficiency. 4) Labor mobility and efficiency. 5) Land liquidity, deposit mobilization, and investment. Empirical results from applying the framework to a single case study - of Thailand, described in a separate paper - suggest that the framework is sound.
NEW TECHNOLOGY SPILLOVERS INTO THE PAYMENT SYSTEM

In modern economies, multiple means of payment associated with the exchange of goods coexist. This paper examines one such payment system in an economy with endogenous technological change. It consists of money and a costly accounting system that receives spillovers from new technologies. Positive nominal interest rates are shown to produce welfare losses by inducing a reallocation of human capital into the payment system, and out of the production of final goods and new knowledge. The former substitution produces level effects on output and the latter produces growth effects. At higher levels of inflation, these marginal effects are seen to be weaker. In modern economies, multiple means of payment associated with the exchange of goods coexist. Among the available options that facilitate these transactions are costly accounting systems such as credit and debit cards for households and cash concentration and sweep accounts for firms. These systems ultimately depend upon various methods of implementing electronic funds transfers (EFTs), whose efficiency in turn is dependent upon computer and information systems technology. Therefore, the efficacy of these means of payment in minimising fundamental trading frictions can be enhanced by improvements in the techniques for implementing EFTs, or by the 'spillovers' of advances in computer and information systems technology via their application to the payment system. This technology interacts with monetary policy in determining the structure of the economy's payment system. In particular, as inflation rises, agents respond by selecting a payment system with a mix of media of exchange that is more heavily weighted in favour of costly accounting systems to avoid the inflation taxes imposed on cash transactions.1 This may misallocate resources and thus reduce welfare. Marquis and Reffett (I 992 b) examine one such payment system in a stochastic neoclassical growth model where the costs of operating the accounting system arise from using physical capital to run the system. In this economy, inflation taxes are shown to produce level effects on output even when a cash-in-advance constraint is imposed only on a subset of the consumption goods. This contrasts with Abel's (i 985) result for a deterministic, cash-in-advance economy, where it is shown that the cash-in-advance constraint must also be imposed on investment goods for anticipated inflation * We thank Sheng-Cheng Hu, Peter Ireland, Stacey Schreft, Stephen Williamson, participants at the I993 Winter Meetings of the Econometrics Society, seminar participants at the Board of Governors of the Federal Reserve System, and two anonymous referees for their helpful comments on earlier versions of this paper. The views expressed in this paper are those of the authors and do not necessarily reflect the opinions of the Board of Governors of the Federal Reserve System, or its staff.
An economic breakeven model of cellulosic feedstock production and ethanol conversion with implied carbon pricing

The objectives of this paper include: 1) developing an economic framework to estimate long run equilibrium breakeven prices that cellulosic ethanol processors can pay for the marginal or last unit of biomass feedstock they purchase and still breakeven and that cellulosic feedstock producers need to receive for supplying the last unit of feedstock delivered to a commercial-scale plant; 2) estimating the gap or difference between the biorefinery’s willingness to pay (WTP) or derived demand for the last unit of cellulosic feedstock and the suppliers’ willingness to accept (WTA) or marginal cost (MC) of supplying the last unit of feedstock; 3) completing a life-cycle analysis (LCA) of each feedstock alternative or a “well-to-wheels” accounting of the potential greenhouse gas (GHG) savings associated with feedstock-specific ethanol relative to gasoline; and 4) calculating the carbon price or credit necessary for a biofuel market to exist in the long run. The model is designed to address various policy issues related to cellulosic biofuel production, including cellulosic biofuel production costs, the cost of cellulosic feedstock production when accounting for all costs incurred, government intervention costs either through tax credits and other incentives needed to sustain biofuel markets or through mandates to achieve the revised Renewable Fuels Standard (RFS.2), and finally, the implicit price or credit for CO2e embodied in cellulosic biofuel.
Internationalization and the Rearrangement of Ownership of Firms and Parts of Firms: Grindlays Bank, 1828-2000

Grindlays Bank, a British overseas bank whose operations spanned South Asia, Africa and the Middle East, has a particularly long and rich history. As a multi-unit organization, Grindlays provides a good example of the point that if one wishes to understand the internationalization process of such a firm — the mechanisms that determine the geographical scope of its operations — one must take into account the rearrangement of ownership of units (primarily branches). As Grindlays’ strategy changed, frequently as a function of changes in its ownership, Grindlays responded by buying or selling units. It also lost units to actions of governments. However, it is the rearrangement of ownership of branches that is the most provocative observation in that it suggests the hypothesis that strategic advantage in banks does not reside at the branch level.
Fully retroactive approximate range and nearest neighbor searching

We describe fully retroactive dynamic data structures for approximate range reporting and approximate nearest neighbor reporting. We show how to maintain, for any positive constant d, a set of n points in ℝd indexed by time such that we can perform insertions or deletions at any point in the timeline in O(logn) amortized time. We support, for any small constant e>0, (1+e)-approximate range reporting queries at any point in the timeline in O(logn+k) time, where k is the output size. We also show how to answer (1+e)-approximate nearest neighbor queries for any point in the past or present in O(logn) time.
A constraint satisfaction approach to the robust spanning tree problem with interval data

Robust optimization is one of the fundamental approaches to deal with uncertainty in combinatorial optimization. This paper considers the robust spanning tree problem with interval data, which arises in a variety of telecommunication applications. It proposes a constraint satisfaction approach using a combinatorial lower bound, a pruning component that removes infeasible and suboptimal edges, as well as a search strategy exploring the most uncertain edges first. The resulting algorithm is shown to produce very dramatic improvements over the mathematical programming approach of Yaman et al. and to enlarge considerably the class of problems amenable to effective solutions.
Effective-Resistance-Reducing Flows, Spectrally Thin Trees, and Asymmetric TSP

We show that the integrality gap of the natural LP relaxation of the Asymmetric Traveling Salesman Problem is polyloglog(n). In other words, there is a polynomial time algorithm that approximates the value of the optimum tour within a factor of polyloglog(n), where polyloglog(n) is a bounded degree polynomial of log log(n). We prove this by showing that any k-edge-connected unweighted graph has a polyloglog(n)/k-thin spanning tree. Our main new ingredient is a procedure, albeit an exponentially sized convex program, that "transforms" graphs that do not admit any spectrally thin trees into those that provably have spectrally thin trees. More precisely, given a k-edge-connected graph G=(V, E) where k>= 7log(n), we show that there is a matrix D that "preserves" the structure of all cuts of G such that for a subset F of E that induces an O(k)-edge-connected graph, the effective resistance of every edge in F w.r.t. D is at most polylog(k)/k. Then, we use our recent extension of the seminal work of Marcus, Spiel man, and Srivastava [MSS13] to prove the existence of a polylog(k)/k-spectrally thin tree with respect to D. Such a tree is polylog(k)/k-combinatorially thin with respect to G as D preserves the structure of cuts of G.
A Calculation of Neutron-Induced Physical Doses in Human Tissues

Abstract : The purpose of the investigation was to calculate improved multicollision neutron fluence-to-dose conversion factors by solving the combined neutron and gamma-ray transport problems in phantom models designed to represent human beings. Also, new neutron fluence-to-kerma factors and improved secondary gamma-ray yields were to be determined for the elements composing the slabs. The computer code ANISN was employed in solution of the transport equation. Multicollision neutron fluence-to-dose conversion factors were calculated for neutron sources, either beams or isotropic fluxes of energies from 15 MeV to thermal incident on a 30 cm slab with infinite or finite transverse dimensions. The curves representing the total of the neutron and gamma-ray energy deposition were found to range from approximately 6% to a factor of two lower than those previously reported. This effect is attributed primarily to the treatment of secondary gamma rays and becomes more pronounced with increasing depth. Results are presented for 38 different combinations of source and geometry and for the maximums as a function of the source energy for each set of calculations. (Author)
Consumer WTP for Blueberry Attributes: A Hierarchical Bayesian Approach in the WTP Space

A stated preference experiment is conducted to elicit consumer WTPs for various blueberry attributes. The mixed logit model is employed to account for consumer heterogeneity. The model is set up in the WTP space where the distributions of WTPs are directly specified. Considering the high diversity of consumer perception and the remarkable benefits from differential marketing, we apply the hierarchical Bayesian approach and the discussion is based on the individual level WTP estimates. The results show that “local produced” attribute is preferred over simply “produced in the U.S.” by most respondents. By contrast, less than 50% of the respondents are willing to pay premium for organic blueberries. In addition, hardly any relationship between demographics and WTPs is detected. Demographic information seems to have little explanation power for consumer perception in small purchases like fruits or vegetables. In this light, the hierarchical Bayesian approach is critical to the practice of differential marketing strategies.
Covariant description of inelastic electron deuteron scattering: Predictions of the relativistic impulse approximation

Using the covariant spectator theory and the transversity formalism, the unpolarized, coincidence cross section for deuteron electrodisintegration, ${d(e,e}^{\ensuremath{'}}p)n,$ is studied. The relativistic kinematics are reviewed, and simple theoretical formulas for the relativistic impulse approximation (RIA) are derived and discussed. Numerical predictions for the scattering in the high ${Q}^{2}$ region obtained from the RIA and five other approximations are presented and compared. We conclude that measurements of the unpolarized coincidence cross section and the asymmetry ${A}_{\ensuremath{\varphi}},$ to an accuracy that will distinguish between different theoretical models, is feasible over most of the wide kinematic range accessible at Jefferson Lab.
Associative memory architecture for video compression

In this paper, we propose a unified associative memory architecture for real-time implementation of motion estimation and frame adaptive vector quantization for video compression. The proposed architecture has the advantages of simplicity, partitionability, and modularity and has hence the potential for VLSI implementation. >
Can Wages Buy Honesty? The Relationship Between Relative Wages and Employee Theft

In this study, we examine whether, for a sample of retail chains, high levels of employee compensation can deter employee theft, an increasingly common type of fraudulent behavior. Specifically, we examine the extent to which relative wages (i.e., employee wages relative to the wages paid to comparable employees in competing stores) affect employee theft as measured by inventory shrinkage and cash shortage. Using two store-level data sets from the convenience store industry, we find that relative wages are negatively associated with employee theft after we control for each store's employee characteristics, monitoring environment, and socio-economic environment. Moreover, we find that relatively higher wages also promote social norms such that coworkers are less (more) likely to collude to steal inventory from their company when relative wages are higher (lower). Our research contributes to an emerging literature in management control that explores the effect of efficiency wages on employee behavior and social norms.
OUTSOURCING AND MARKET VALUE OF THE FIRM: TOWARD A COMPREHENSIVE MODEL

We analyze the effect of buyer, contract, and vendor characteristics on abnormal stock returns among firms that have announced large scale Information Technology IT and Business Process outsourcing BPO contracts. We draw upon a comprehensive dataset on outsourcing announcements, augmented with data from public sources. Salient buyer factors examined include use of a wide range of organizational controls. On the vendor side, we examine the impact of vendor size, contract size and reputation. Our study shows that use of behavior controls, outcome controls negative, vendor reputation, and industry of buyer firm affect market value. When limited to buyer related factors, use of behavior and clan controls is positively related to abnormal returns around IT outsourcing announcements. An interesting finding is that IT and BPO success require different sets of controls. Copyright © 2014 John Wiley & Sons, Ltd.
Design Strategies for Enhanced Hydrogen-Bond Donor Catalysts

Dual hydrogen-bond donor (HBD) scaffolds can be strategically designed to enable their optimal performance as catalysts. The deliberate installation of activating groups on HBDs containing conventional functionalities, such as ureas and thioureas, has emerged as one fruitful direction in the identification of catalysts with enhanced activity and improved stereocontrol. Alternatively, new families of HBDs based on structurally unique, inherently more acidic functional groups, such as squaramide and aminopyridinium systems, have proven advantageous over conventional HBD catalysts in select processes. The appropriate incorporation of activating design elements into HBD catalyst frameworks is currently determined empirically and dictated by the specific process under development; each individual reaction benefits from tuning of the HBD catalyst acidity, steric environment, and/or electronic environment. This review presents recent design elements integrated into dual HBD catalyst scaffolds and their influence on HBD catalyst performance.
Generic on-line/off-line threshold signatures

We present generic on-line/off-line threshold signatures, in which the bulk of signature computation can take place “off-line” during lulls in service requests [6]. Such precomputation can help systems using threshold signatures quickly respond to requests. For example, tests of the Pond distributed file system showed that computation of a threshold RSA signature consumes roughly 86% of the time required to service writes to small files [12]. We apply the “hash-sign-switch” paradigm of Shamir and Tauman [16] and the distributed key generation protocol of Gennaro et al. [7] to convert any existing secure threshold digital signature scheme into a threshold on-line/off-line signature scheme. We show that the straightforward attempt at proving security of the resulting construction runs into a subtlety that does not arise for Shamir and Tauman's construction. We resolve the subtlety and prove our signature scheme secure against a static adversary in the partially synchronous communication model under the one-more-discrete-logarithm assumption [2]. The on-line phase of our scheme is efficient: computing a signature takes one round of communication and a few modular multiplications in the common case.
Distributed Control of Microscopic Robots in Biomedical Applications

To illustrate controls for large collections of microscopic robots, this chapter considers a prototypical diagnostic task of finding a small chemical source in a multicellular organism via the circulatory system. To do so, we first review plausible capabilities for microscopic robots and the physical constraints due to operation in fluids at low Reynolds number, diffusion-limited sensing and thermal noise from Brownian motion. We then discuss techniques for evaluating the behavior of large collections of robots, and examine a specific task scenario. The emphasis here is on feasible performance with plausible biophysical parameters and robot capabilities. Evaluation metrics include minimizing hardware capabilities to simplify fabrication and ensuring
A note on idempotents in finite AW^*-factors

We prove that the value of the quasi-trace on an idempotent ele- ment in a AW*-factor of type II1 is the same as the dimension of its left (or right) support. It is a long standing open problem (due to Kaplansky) to prove that an AW*- factor of type II1 is in fact a von Neumann algebra. A remarkable answer, in the affirmative, was found by Haagerup ((Ha)), who proved that if an AW*-factor A is generated by an exact C*-algebra, then A is indeed a von Neumann algebra. The main object, that was investigated in connection with Kaplansky's problem, is the quasi-trace, whose construction we briefly recall below. One starts with an AW*-factor of type II1, say A. Denote by P(A) the collection of projections in A, that is P(A) = {p ∈ A : p = p ∗ = p 2 }.
Supply Curves of Conserved Energy

Supply curves of conserved energy provide an accounting framework that expresses the potential for energy conservation. The economic worthiness of a conservation measure is expressed in terms of the cost of conserved energy, and a measure is considered economical when the cost of conserved energy is less than the price of the energy it replaces. A supply curve of conserved energy is independent of energy prices; however, the economical reserves of conserved energy will depend on energy prices. Double-counting of energy savings and error propagation are common problems when estimating conservation potentials, but supply curves minimize these difficulties and make their consequences predictable. The sensitivity of the cost of conserved energy is examined, as are variations in the optimal investment strategy in response to changes in inputs. Guidelines are presented for predicting the consequences of such changes. The conservation supply curve concept can be applied to peak power, water, pollution, and other markets where consumers demand a service rather than a particular good.
Parametric Amplification of Gravitational Fluctuations during Reheating

Cosmological perturbations can undergo amplification by parametric resonance during preheating even on scales larger than the Hubble radius, without violating causality. A unified description of gravitational and matter fluctuations is crucial to determine the strength of the instability. To extract specific signatures of the oscillating inflaton field during reheating, it is essential to focus on a variable describing metric fluctuations which is constant in the standard analyses of inflation. For a massive inflaton without self-coupling, we find no additional growth of superhorizon modes during reheating beyond the usual predictions. For a massless self-coupled inflaton, there is a sub-Hubble scale resonance. {copyright} {ital 1999} {ital The American Physical Society}
The transient EUV sky as observed by ALEXIS

Los Alamos National Laboratory’s ALEXIS satellite, containing six wide field of view EUV telescopes was launched 1993 April 25. ALEXIS is a sky monitor/survey experiment, and with each 50 s rotation, the satellite’s six telescopes (three energy bands 130, 178 and 186 A) scan nearly half of the sky. Due to the damage sustained at launch by the satellite, the ALEXIS project team has had to spend over a year devising new methods to determine spacecraft attitude knowledge, essential for putting photons back on the sky correctly. These efforts have been successful. A recent review of the ALEXIS point source effort can be found in the Proceedings of IAU Colloquium 152, 1995. This paper reviews the transient systems that have been observed by ALEXIS which fall into two types: cataclysmic variables and unknown, short duration transients.
Effects of filtering by Present call on analysis of microarray experiments

Affymetrix GeneChips® are widely used for expression profiling of tens of thousands of genes. The large number of comparisons can lead to false positives. Various methods have been used to reduce false positives, but they have rarely been compared or quantitatively evaluated. Here we describe and evaluate a simple method that uses the detection (Present/Absent) call generated by the Affymetrix microarray suite version 5 software (MAS5) to remove data that is not reliably detected before further analysis, and compare this with filtering by expression level. We explore the effects of various thresholds for removing data in experiments of different size (from 3 to 10 arrays per treatment), as well as their relative power to detect significant differences in expression. Our approach sets a threshold for the fraction of arrays called Present in at least one treatment group. This method removes a large percentage of probe sets called Absent before carrying out the comparisons, while retaining most of the probe sets called Present. It preferentially retains the more significant probe sets (p ≤ 0.001) and those probe sets that are turned on or off, and improves the false discovery rate. Permutations to estimate false positives indicate that probe sets removed by the filter contribute a disproportionate number of false positives. Filtering by fraction Present is effective when applied to data generated either by the MAS5 algorithm or by other probe-level algorithms, for example RMA (robust multichip average). Experiment size greatly affects the ability to reproducibly detect significant differences, and also impacts the effect of filtering; smaller experiments (3–5 samples per treatment group) benefit from more restrictive filtering (≥50% Present). Use of a threshold fraction of Present detection calls (derived by MAS5) provided a simple method that effectively eliminated from analysis probe sets that are unlikely to be reliable while preserving the most significant probe sets and those turned on or off; it thereby increased the ratio of true positives to false positives.
ISSUES FOR THE NEXT GENERATION OF GALAXY SURVEYS

The weight of the evidence is that the mean mass density (excluding a cosmological constant or its equivalent) is less than the critical Einsteinde Sitter value. This result, if confirmed, is notab...
A physical model for widespread near‐surface and fault zone damage induced by earthquakes

[1] I present a rigorous unifying interpretation of the well-documented widespread near-surface and fault zone damage induced by earthquakes by simulating three-dimensional dynamic rupture propagation on a vertical strike-slip fault. Stresses in the crust are depth-dependent and material response is governed by the Drucker-Prager yielding criterion. I show that material yielding induced by seismic waves under the low confining pressure causes widespread near-surface damage. Because the confining pressure increases with depth, the yielding zone at depth is narrowly confined near the fault, but its thickness broadens dramatically near the surface, forming a “flower-like” damage zone. The fault zone damage at depth is induced by large dynamic stresses associated with the rupture front, while is induced by strong seismic waves ahead of the rupture front near the Earth's surface. These results have important implications for the formation and evolution of fault zones and possibly for the dynamic triggering of earthquakes as well.
The backward behavior of the Ricci and cross-curvature flows on SL (2,R)

This paper is concerned with properties of maximal solutions of the Ricci and cross curvature flows on locally homogeneous three-manifolds of type SL2(R). We prove that, generically, a maximal solution originates at a sub-Riemannian geometry of Heisenberg type. This solves a problem left open in earlier work by two of the authors.
An Analytical Model of Periodic Waves in Shallow Water

Abstract : An explicit, analytical model is presented of finite amplitude waves in shallow water. The waves in question have two independent spatial periods, in two independent horizontal directions. Both short-crested and long-crested waves are available from the model. Every wave pattern is an exact solution of the Kadomtsev-Petviashvili equation, and is based on a Riemann theta function of genus 2. These bi-periodic waves are direct generalizations of the well-known (simply periodic) cnoidal waves. Just as cnoidal waves are often used as one-dimensional models of typical nonlinear, periodic waves in shallow water, these bi-periodic waves may be considered to represent typical nonlinear, periodic waves in shallow water without the assumption of one-dimensionality. (Author)
A survey of multiplicity fluctuations in PHENIX

Interest in the topic of charged particle multiplicity fluctuations has been recently revived by the observation of non-monotonic behavior in the scaled variance as a function of system size at SPS energies [4]. The scaled variance is defined as var(N)/〈N〉, where var(N) represents the variance of the multiplicity distribution in a given centrality bin, and 〈N〉 is the mean of the distribution. For reference, the scaled variance of a Poisson distribution is 1.0, independent of N. PHENIX has studied the behavior of charged particle multiplicity fluctuations as a function of centrality and transverse momentum in √sNN = 62 GeV and 200 GeV Au+Au and Cu+Cu collisions in order to investigate if this behavior persists at RHIC energies. Details about the PHENIX experimental configuration can be found elsewhere [2]. All of the measurements described here utilized the PHENIX central arm detectors. The maximum PHENIX acceptance of |η| < 0.35 in pseudorapidity and 180 degrees in azimuthal angle is considered small for event-by-event measurements. However, the event-by-event multiplicities are high enough in RHIC heavy-ion collisions that PHENIX has a competitive sensitivity for the detection of many fluctuation signals. For example, a detailed examination of the PHENIX sensitivity to temperature fluctuations derived from the measurement of mean pT fluctuations is described in [3]. A survey of multiplicity fluctuations in PHENIX Jeffery T. Mitchell and the PHENIX Collaboration
Complexity of manipulating elections with few candidates

In multiagent settings where the agents have different preferences, preference aggregation is a central issue. Voting is a general method for preference aggregation, but seminal results have shown that all general voting protocols are manipulable. One could try to avoid manipulation by using protocols where determining a beneficial manipulation is hard. Especially among computational agents, it is reasonable to measure this hardness by computational complexity. Some earlier work has been done in this area, but it was assumed that the number of voters and candidates is unbounded. We derive hardness results for the more common setting where the number of candidates is small but the number of voters can be large. We show that with complete information about the others' votes, individual manipulation is easy, and coalitional manipulation is easy with unweighted voters. However, constructive coalitional manipulation with weighted voters is intractable for all of the voting protocols under study, except in the Cup protocol. Destructive manipulation tends to be easier, except in the Single Transferable Vote protocol. Randomizing over instantiations of the protocols (such as schedules of a Cup) can be used to make manipulation hard. Finally, we show that under weak assumptions, if weighted coalitional manipulation with complete information about the others' votes is hard in some voting protocol, then individual and unweighted manipulation is hard when there is uncertainty about the others' votes.
A probabilistic algorithm for calculating structure: borrowing from simulated annealing

We have developed a general Bayesian algorithm for determining the coordinates of points in a three-dimensional space. The algorithm takes as input a set of probabilistic constraints on the coordinates of the points, and an a priori distribution for each point location. The output is a maximum-likelihood estimate of the location of each point. We use the extended, iterated Kalman filter, and add a search heuristic for optimizing its solution under nonlinear conditions. This heuristic is based on the same principle as the simulated annealing heuristic for other optimization problems. Our method uses any probabilistic constraints that can be expressed as a function of the point coordinates (for example, distance, angles, dihedral angles, and planarity). It assumes that all constraints have Gaussian noise. In this paper, we describe the algorithm and show its performance on a set of synthetic data to illustrate its convergence properties, and its applicability to domains such as molecular structure determination.
Submodular cost allocation problem and applications

We study the Minimum Submodular-Cost Allocation problem (MSCA). In this problem we are given a finite ground set V and k non-negative submodular set functions f1, ... , fk on V. The objective is to partition V into k (possibly empty) sets A1, ... , Ak such that the sum Σi=1k fi(Ai) is minimized. Several well-studied problems such as the non-metric facility location problem, multiway-cut in graphs and hypergraphs, and uniform metric labeling and its generalizations can be shown to be special cases of MSCA. In this paper we consider a convexprogramming relaxation obtained via the Lovasz-extension for submodular functions. This allows us to understand several previous relaxations and rounding procedures in a unified fashion and also develop new formulations and approximation algorithms for related problems. In particular, we give a (1.5 - 1/k)-approximation for the hypergraph multiway partition problem. We also give a min{2(1-1/k), HΔ}-approximation for the hypergraph multiway cut problem when Δ is the maximum hyperedge size. Both problems generalize the multiway cut problem in graphs and the hypergraph cut problem is approximation equivalent to the nodeweighted multiway cut problem in graphs.
High-Throughput Screening Platform for Engineered Nanoparticle-Mediated Genotoxicity Using CometChip Technology

The likelihood of intentional and unintentional engineered nanoparticle (ENP) exposure has dramatically increased due to the use of nanoenabled products. Indeed, ENPs have beenincorporatedinmany usefulproductsand haveenhancedourway oflife. However,there are many unansweredquestions about the consequencesofnanoparticleexposures,inparticular,withregardtotheirpotentialtodamagethegenomeandthuspotentiallypromotecancer.Inthisstudy, we present a high-throughput screening assay based upon the recently developed CometChip technology, which enables evaluation of single-stranded DNA breaks, abasic sites, and alkali-sensitive sites in cells exposed to ENPs. The strategic microfabricated, 96-well design and automated processing improves efficiency,reducesprocessingtime,andsuppressesuserbiasincomparisontothestandardcometassay.Weevaluatedtheversatilityofthisassaybyscreening fiveindustriallyrelevantENPexposures(SiO2,ZnO,Fe2O3,Ag,andCeO2)onbothsuspensionhumanlymphoblastoid(TK6)andadherentChinesehamsterovary (H9T3)celllines.MTTandCyQuantNFassayswereemployedtoassesscellularviabilityandproliferationafterENPexposure.ExposuretoENPsatadoserange
Corrosion of steel tendons used in prestressed concrete pressure vessels

The purpose of this investigation was to determine the corrosion behavior of a high-strength steel [Specifications for Uncoated Seven-Wire-Stress-Relieved Strand for Prestressed Concrete (ASTM A 416-74, Grade 270)], typical of those used as tensioning tendons in prestressed concrete pressure vessels, in several corrosive environments, and to determine the protection obtained by coating the steel with two commercial petroleum-base greases or with portland cement grout. In addition, the few reported incidents of prestressing steel failures in concrete pressure vessels used for containment of nuclear reactors were reviewed. The susceptibility of the steel to stress corrosion cracking and hydrogen embrittlement and its general corrosion rate were determined in several salt solutions. Wires coated with the greases and grout were soaked for long periods in the same solutions and changes in their mechanical properties were subsequently determined. All three coatings appeared to give essentially complete protection; however, flaws in the grease coatings could be detrimental, and flaws or cracks less than 1-mm-wide (0.04 in.) in the grout were without effect.