cssi/SciSciGPT-SciSciNet huggingface dataset:
Cirrus: a Serverless Framework for End-to-end ML Workflows

Machine learning (ML) workflows are extremely complex. The typical workflow consists of distinct stages of user interaction, such as preprocessing, training, and tuning, that are repeatedly executed by users but have heterogeneous computational requirements. This complexity makes it challenging for ML users to correctly provision and manage resources and, in practice, constitutes a significant burden that frequently causes over-provisioning and impairs user productivity. Serverless computing is a compelling model to address the resource management problem, in general, but there are numerous challenges to adopt it for existing ML frameworks due to significant restrictions on local resources. This work proposes Cirrus---an ML framework that automates the end-to-end management of datacenter resources for ML workflows by efficiently taking advantage of serverless infrastructures. Cirrus combines the simplicity of the serverless interface and the scalability of the serverless infrastructure (AWS Lambdas and S3) to minimize user effort. We show a design specialized for both serverless computation and iterative ML training is needed for robust and efficient ML training on serverless infrastructure. Our evaluation shows that Cirrus outperforms frameworks specialized along a single dimension: Cirrus is 100x faster than a general purpose serverless system [36] and 3.75x faster than specialized ML frameworks for traditional infrastructures [49].
Proximity-induced spin-orbit splitting in graphene nanoribbons on transition-metal dichalcogenides

We study the electronic structure of heterostructures formed by a graphene nanoribbon (GNR) and a transition metal dichalcogenides (TMD) monolayer using first principles. We consider both semiconducting TMDs and metallic TMDs, and different stacking configurations. We find that when the TMD is semiconducting the effects on the band structure of the GNRs are small. In particular the spin splitting induced by proximity on the GNRs bands is only of the order of few meV irrespective of the stacking configuration. When the TMD is metallic, such as ${\mathrm{NbSe}}_{2}$, we find that the spin splitting induced in the GNRs can be very large and strongly dependent on the stacking configuration. For optimal stacking configurations the proximity-induced spin splitting is of the order of 20 meV for armchair graphene nanoribbons and as high as 40 meV for zigzag graphene nanoribbons. This results are encouraging for the prospects of using GNR-TMD heterostructures to realize quasi-one-dimensional topological superconducting states supporting Majorana modes.
Does the Context of Racial Discrimination Matter for Adolescent School Outcomes?: The Impact of In-School Racial Discrimination and General Racial Discrimination on Black Adolescents’ Outcomes

The present study explored the role of context and gender on the association between racial discrimination and adolescents’ outcomes among Black ninth graders (N = 557) (male = 249; female = 308). In particular, we investigated whether there were differences in the link between racial discrimination within school, and racial discrimination outside of school, and adolescents' academic and non-academic outcomes. Findings on the role of context and gender were mixed. While in-school racial discrimination was more strongly related to academic persistence than general racial discrimination, our results did not reveal differences in the associations between racial discrimination and grades or psychological well-being. Gender results indicated that girls who reported decreases in in-school and general racial discrimination were more likely to report a more positive perceptions of school climate. Implications for research on the association between racial discrimination and adolescent outcomes are discussed.
Misión de una Universidad jesuita

This text consists of basically an analysis of Father Peter Hans Kolvenbach’s thoughts, to date Superior General of the Society of Jesus who has developed a rich reflection on the mission of Jesuit Universities. It is an adapted version of the talk given by the author at the IX Conference “Formation for Mission” organised by UNIJES and held in Loyola from 5th to 9th of November 2007. With the form of nine theses, he proposes a reflection on a) the mission of the Society of Jesus, that is not different from that of the Church itself; b) the specific mission of Jesuit Universities, in which definition, the noun (“University”) and the adjective (“Jesuit”) should be dialectically taken into account at the same time. He supports Kolvenbach’s idea that the ideal of Jesuit education for more than four centuries, will, in the future, be a competent, conscious person, capable of compassion and well educated in solidarity.
Learning a Neural-Network Controller for a Multiplicative Observation Noise System

We consider the stabilization of a linear control system with multiplicative observation noise. Linear strategies have been proven to be ineffective in this system, and non-linear strategies can unboundedly outperform the best linear strategies. The current best-known control strategy is hand-crafted and far from optimal.In this paper, we use neural-network-based controllers to narrow the gap between the achievability and the converse for this problem. We propose a periodic controller structure and a greedy training procedure. This enables us to train our controller on a finite horizon problem but learn strategies that outperform the best-known hand-crafted strategy and also generalize, i.e., provide stabilizing control at times beyond the training horizon. Further, we show that for our periodic approach, the learned strategies display a piecewise linear structure and are well approximated by interpretable functions.
Polo : an open-source graphical user interface for crystallization screening.

Polo is a Python-based graphical user interface designed to streamline viewing and analysis of images to monitor crystal growth, with a specific target to enable users of the High-Throughput Crystallization Screening Center at Hauptman-Woodward Medical Research Institute (HWI) to efficiently inspect their crystallization experiments. Polo aims to increase efficiency, reducing time spent manually reviewing crystallization images, and to improve the potential of identifying positive crystallization conditions. Polo provides a streamlined one-click graphical interface for the Machine Recognition of Crystallization Outcomes (MARCO) convolutional neural network for automated image classification, as well as powerful tools to view and score crystallization images, to compare crystallization conditions, and to facilitate collaborative review of crystallization screening results. Crystallization images need not have been captured at HWI to utilize Polo's basic functionality. Polo is free to use and modify for both academic and commercial use under the terms of the copyleft GNU General Public License v3.0.
Vermiremediation – Remediation of Soil Contaminated with Oil Using Earthworm (Eisenia fetida)

Vermiremediation is considered as an evolving environmental friendly and sustainable technology. It serves as an additional parallel factor in increasing overall efficiency of bio-methods. Vermirem...
Differential effects of attentional control domains on the association between rumination and PTSD symptoms in trauma exposed veterans

Abstract Although rumination is a risk factor for posttraumatic stress disorder (PTSD), the processes that influence the association between rumination and PTSD symptoms are unclear. Processes that facilitate reorienting or redirecting attention may play an important role in the relationship between rumination and PTSD. While attentional control is one such cognitive process, it consists of both shifting and focusing components, and it remains unclear which component most strongly influences the association between rumination and PTSD. This study examined attentional control as a moderator of the relationship between rumination and PTSD symptoms and cognitions among combat-exposed veterans (N = 114). Results revealed that attentional shifting but not focusing moderated the effect of rumination on PTSD symptoms, such that those high in rumination and low in attentional shifting reported increased avoidance and posttraumatic cognitions. Etiological and clinical implications are discussed.
Comparison of synthetic and low-cost natural zeolite for bio-oil focused pyrolysis of raw and pretreated biomass

Abstract Acid-pretreatment of rice straw (RS) and its subsequent pyrolysis with and without natural zeolite (NZ) and HZSM-5 catalysts were investigated and compared comprehensively. Acid-washing eluted 96% K, 74.73% Ca, 94.78% Mg and 98.33% Na metals from RS besides improving its higher heating value (HHV) and relative content of lignocellulose. Oxygenates reduction of 25.84% along with 12 folds increase in levoglucosan was observed during pyrolysis of washed-RS (W-RS) compared to raw-RS (R-RS). Oxygenates transformation into hydrocarbons was significantly promoted with both catalysts. The selectivity of most valuable aromatic hydrocarbons e.g benzene, toluene and xylene (BTX) of HZSM-5 was superior to that of NZ in either of RS with the highest selectivity of 16%(B), 22%(T) and 30%(X) in W-RS/HZSM-5 due to its higher total pore volume, surface area and lower acidity and controlled reforming reactions. NZ selectivity for BTX was also improved from 7.69%, 13.04% and 8.69% during R-RS/NZ to 10.52%, 15.78% and 21.05% for W-RS/NZ, respectively. Moreover, HHV of W-RS/NZ bio-oil was 26.32 MJ/kg whilst that of W-RS/HZSM-5 oil (30.95 MJ/kg) was highest among all. Besides, physical characteristics of bio-oil including density, flash points and pour points were improved with both catalysts in the case of W-RS compared to R-RS.
Abstract WP111: The Role of Intravenous Tissue Plasminogen Activator in Acute Ischemic Stroke With Large Vessel Occlusion

Introduction: Current guidelines recommend administration of intravenous tissue plasminogen activator (IVT) for all eligible patients with acute ischemic stroke (AIS) with large vessel occlusion (L...
An Empirical Model of R&D Procurement Contests: An Analysis of the DOD SBIR Program

Firms and governments often use RD however, these changes reduce the DOD's own welfare. These results suggest there is substantial scope for improving the design of real‐world contests but that a designer must balance competing objectives.
Model Reference Adaptive Control of Mechanical Manipulators

Abstract The dynamic equations of mechanical manipulators are highly nonlinear and complex. Furthermore, the inertia characteristics of the manipulator depend on the payload which is often unknown. Because of these reasons, there is an increasing interest in adaptive control of mechanical manipulators. The objective of this paper is to present how recent model reference adaptive control (MRAC) schemes can be used for the dynamic control of mechanical manipulkators. The advantages of using the MRAC schemes are demonstrated by simulation results for a three degrees of freedom mechanical manipulator and experimental results for a one dimensional position control problem.
Hepatitis B--an important public health issue.

Hepatitis B is one of the most common infectious diseases in the world. It has been estimated that 350 million people worldwide are chronic hepatitis B virus (HBV) carriers. The global prevalence of chronic HBV infection varies widely, from high ( > 8%, e.g., Africa, Asia and the Western Pacific) to intermediate (2-7% e.g., Southern and Eastern Europe) and low (< 2%, e.g., Western Europe, North America and Australia). The predominant routes of transmission vary according to the endemicity of the HBV infection. In areas of high endemicity, perinatal transmission is the main route of transmission, whereas in areas of low endemicity, sexual contact amongst high-risk adults is predominant. Between one-third and one-quarter of people infected chronically with HBV are expected to develop progressive liver disease (including cirrhosis and primary liver cancer). Although mass vaccination programs have begun to control the spread of HBV infection, therapeutic intervention is the only option for those with established chronic HBV-associated liver disease. Until recently, the only treatment for chronic hepatitis B was the immune modulator, interferon (IFN) alpha. However, IFN alpha treatment has several disadvantages; it is expensive, it must be administered by injection, there are side-effects, and IFN alpha is poorly tolerated. Lamivudine, a nucleoside analogue, is the first effective, and well tolerated, oral treatment for chronic hepatitis B. In conclusion, although we are still some way from eradicating or curing chronic hepatitis B, the advent of lamivudine allows new populations to benefit from therapy and helps to address the global public health problem of hepatitis B.
The Presence of Family Members and Others During Attorney-Client Communications: Himmel's Other Dilemma

In In re Himmel, 533 N.E. 3d 790 (111. 1988), the Illinois Supreme Court addressed the dilemma that confronted attorney James Himmel, who had been forced to choose between reporting another attorney's misconduct and maintaining his own client's secrets. The high court's pronouncements regarding Himmel's dilemma have been widely read, though not always with pleasure. Yet, attorney Himmel faced a second dilemma: How could he accommodate his client's desire to discuss her legal problems with him in the presence of both her mother and her fiance, while assuring her that their discussion would probably be deemed privileged and thus immunized from compelled disclosure? On this other dilemma, the Illinois Supreme Court said little, noting only that no privilege would be recognized unless the mother and fiance were "agents" of Himmel's client. The court provided neither substantive nor procedural guidelines for determining whether such an agency exists. In the hope of aiding those who face Himmel's other dilemma, this article analyzes who may be considered an agent of an individual client for the purpose of privileging attorney-client communications.
Radiation curable wire coatings

Solventless, 100% reactive Radiation Curable Coatings (RCCls) are materials that can be cured rapidly by radiation [e.g., Ultraviolet Light (UV) or Electron Beam (EB)] to highly crosslinked, tough, flexible films. They can be coated and cured on either bare or insulated wire for use in magnet wire, non-magnet wire, and cable applications. New Radiation Curable Coatings for various wire applications will be discussed.
Distributing Data for Secure Database Services

The advent of database services has resulted in privacy concerns on the part of the client storing data with third party database service providers. Previous approaches to enabling such a service have been based on data encryption, causing a large overhead in query processing. A distributed architecture for secure database services is proposed as a solution to this problem where data is stored at multiple servers. The distributed architecture provides both privacy as well as fault tolerance to the client. In this paper we provide algorithms for (1) distributing data: our results include hardness of approximation results and hence a heuristic greedy algorithm for the distribution problem (2) partitioning the query at the client to queries for the servers implemented by a bottom up state based algorithm. Finally the results at the servers are integrated to obtain the answer at the client. We provide an experimental validation and performance study of our algorithms.
Arbitrage between ethanol and gasoline: evidence from motor fuel consumption in Brazil

Unlike regular cars, ex-fuel vehicles (FFVs) allow motorists to fuel on motor blends that contain between zero and one hundred percent of ethanol. This paper investigates how motorists arbitrage between hydrous ethanol and gasoline using aggregate fuel consumption data in Brazil. The ability of FFV motorists to arbitrage between fuel blends shapes of aggregate demands for hydrous ethanol and gasoline. I estimate using nonlinear seemingly unrelated regressions the demands for hydrous ethanol and gasoline in Brazil, and motorists preferences for hydrous ethanol. I find that on average, accounting for the relative energy contents of the two fuels, FFV motorists in Brazil slightly discount hydrous ethanol over gasoline. Most consumers switch between fuels when their relative prices are at near parity. I find that 20% of consumers still purchase hydrous ethanol when its price is about 10% above the price of gasoline. The distribution of preferences is not symmetric as 20% of consumers still purchase gasoline when there is a 15% discount on the price of hydrous ethanol.
"Crowding in" and the Returns to Government Investment in Low-Income Countries

This paper estimates the effect of government investment on private investment in a sample of 39 low-income countries. Fluctuations in a predetermined component of disbursements on loans from official creditors to developing country governments are used as an instrument for fluctuations in public investment. The analysis finds evidence of "crowding in" : an extra dollar of government investment raises private investment by roughly two dollars, and output by 1.5 dollars. To understand the implications for the return to public investment, a CES production function with public and private capital as inputs is calibrated. For most countries in the sample, the returns to government investment exceed the world interest rate. However, for some countries that already have high government investment rates, the return to further investment is below the world interest rate.
ON ORBIT THRUSTER CALIBRATION WITH APPLICATIONS TO GRAVITY PROBE B

Abstract A general procedure to determine accurately the true relationship between the commanded and the actual force output of a set of thrusters is presented. This relationship is determined from data generated from a spacecraft while it is on orbit. On orbit thruster calibration measures the true outputs of the thrusters in the actual space environment in which they operate. The feasibility of the calibration technique is verified by a digital simulation of the Gravity Probe B (GP-B) spacecraft dynamics. GP-B is an Earth orbiting experiment which will test several aspects of general relativity. A set of 18 proportional thrusters generates forces and moments for three degree of freedom attitude and three degree of freedom drag free translation control of the GP-B spacecraft. A total of 108 parameters are needed to characterize the magnitude and direction of both the force and moment outputs of the 18 thrusters. The ability to calibrate these parameters to an accuracy of better than 1%is demonstrated.
On connectivity in ad hoc networks under jamming using directional antennas and mobility

In this paper we investigate the problem of maintaining connectivity under jamming in multihop ad hoc wireless networks. Connectivity is measured using a connectivity index, which indicates the probability that there exists a path between two nodes. We first show that connectivity can be drastically reduced with a relatively small number of jammers. We show that using sectored antennas can maintain connectivity in the presence of a significantly higher number of jammers at the expense of higher average number of hops. Finally, we show that mobility allows further resiliency to jamming.
Ghoshal’s Ghost: Financialization and the End of Management Theory

Sumantra Ghoshal's condemnation of Bbad management theories^ that were Bdestroying good management practices^ has not lost any of its salience, after a decade. Management theories anchored in agency theory (and neo-classical economics generally) continue to abet the financialization of society and undermine the functioning of business. An alternative approach (drawn from a more classic institutional, new ecological, and refocused ethical approaches) is reviewed.
Searching for a Compressed Polyline with a Minimum Number of Vertices

There are many practical applications that require the simplification of polylines. Some of the goals are to reduce the amount of information, improve processing time, or simplify editing. Simplification is usually done by removing some of the vertices, making the resultant polyline go through a subset of the source polyline vertices. However, such an approach does not necessarily produce a new polyline with the minimum number of vertices. Using an algorithm that finds the compressed polyline with the minimum number of vertices is an improvement in memory and postprocessing time. However, when the resultant polyline is edited by an operator, having a polyline with the minimum number of vertices decreases the operator time, which reduces the cost of processing the data. The algorithm described in this paper is used for the reconstruction of orthogonal buildings. If the resultant closed polyline is required to pass through original vertices, it would often result in extra segments, and all segments are likely to be shifted due to fixed endpoints. A viable solution to finding a polyline within a specified tolerance with the minimum number of vertices is described in this paper.
A Parham cyclization approach to diaryl-fused seven-membered ring heterocyclic ketones

Aryl-fused seven membered heterocyclic frameworks appear in a variety of pharmaceutically pertinent compounds. However, only a very few methods for their preparation have been described. This work describes a novel synthesis route to diaryl-fused seven membered heterocyclic ketones through the generation of functionalized aryllithiums by bromine–lithium exchange, followed by intramolecular cyclization onto an electrophilic nitrile functional group. The resulting N-lithioimine can then be hydrolyzed to the desired ketone, generally in good yields. The order of addition of n-butyllithium is crucial to the process with inverse addition proving to mitigate side product formation and increase yields.
Enantioselective Synthesis of Carbo- and Heterocycles through a CuH-Catalyzed Hydroalkylation Approach.

The enantioselective, intramolecular hydroalkylation of halide-tethered styrenes has been achieved through a copper hydride-catalyzed process. This approach allowed for the synthesis of enantioenriched cyclobutanes, cyclopentanes, indanes, and six-membered N- and O-heterocycles. This protocol was applied to the synthesis of the commercial serotonin reuptake inhibitor (−)-paroxetine.
The IMF and Tax Reform

The paper deals with the activities of Fund staff with taxation. It is made up of four parts. Part I outlines the connection between Fund major activities and taxation. Part II surveys general influences on Fund staff with implications for tax work. Part III outlines the relationship between Fund-supported programs and changes in tax systems. Part IV focuses on the structure, rather than the level, of taxation. It outlines in broad terms the prevalent thinking of Fund staff on the structure of taxation.
Ewald and Multipole Methods for Periodic N-Body Problems

Many realistic biomolecular simulations require use of periodic boundary conditions to create a surface-free environment for the molecule of interest and associated solvent molecules to interact. Electrostatic interactions are the principal computational cost of such simulations. We have implemented two codes: a parallel variant of an Ewald summation method which computes the effect of infinite periodic boundary conditions, and a parallel variant of a multipole algorithm which explicitly computes the interactions within a large but finite periodic system. Each has a regime of applicability, with Ewald favoring smaller systems and fewer processors, and the multipole methods favoring larger systems and more processors. Simulations can now include a full treatment of periodic electrostatics to three or four significant figures of accuracy for a computational cost equivalent to that of a 12A cutoff simulation.
Managing informal mathematical knowledge: techniques from informal logic

Much work in MKM depends on the application of formal logic to mathematics. However, much mathematical knowledge is informal. Luckily, formal logic only represents one tradition in logic, specifically the modeling of inference in terms of logical form. Many inferences cannot be captured in this manner. The study of such inferences is still within the domain of logic, and is sometimes called informal logic. This paper explores some of the benefits informal logic may have for the management of informal mathematical knowledge.
The deltagrid abstract execution model: service composition and process interference handling

This paper introduces the DeltaGrid abstract execution model as a foundation for building a semantically robust execution environment for concurrent processes executing over Delta-Enabled Grid Services (DEGS). A DEGS is a Grid Service with an enhanced capability to capture incremental data changes, known as deltas, associated with service execution in the context of global processes. The abstract model contains a service composition model that provides multi-level protection against service execution failure, thus maximizing the forward recovery of a process. The model also contains a process recovery model to handle the possible impact caused by failure recovery of a process on other concurrently executing processes using data dependencies derived from a global execution history and using user-defined correctness criteria. This paper presents the abstract execution model and demonstrates its use. We also outline future directions for incorporating application exception handling and build a simulation framework for the DeltaGrid system.
Meta reasoning in ACL2

The ACL2 system is based upon a first-order logic and implements traditional first-order reasoning techniques, notably (conditional) rewriting, as well as extensions including mathematical induction and a “functional instantiation” capability for mimicking second-order reasoning. Additionally, one can engage in meta-reasoning — using ACL2 to reason, and prove theorems, about ACL2's logic from within ACL2. One can then use these theorems to augment ACL2's proof engine with custom extensions. ACL2 also supports forms of meta-level control of its rewriter. Relatively recent additions of these forms of control, as well as extensions to ACL2's long-standing meta-reasoning capability, allow a greater range of rules to be written than was possible before, allowing one to specify more comprehensive proof strategies.
A Polynomial-Time Algorithm for the Matching of Crossing Contact-Map Patterns

Contact maps are a model to capture the core information in the structure of biological molecules, e.g., proteins. A contact map consists of an ordered set S of elements (representing a protein’s sequence of amino acids), and a set A of element pairs of S, called arcs (representing amino acids which are closely neighbored in the structure). Given two contact maps (S,A) and (S p ,A p ) with |A|≥ |A p |, the Contact Map Pattern Matching (CMPM) problem asks whether the “pattern” (S p ,A p ) “occurs” in (S,A), i.e., informally stated, whether there is a subset of |A p | arcs in A whose arc structure coincides with A p . CMPM captures the biological question of finding structural motifs in protein structures. In general, CMPM is NP-hard. In this paper, we show that CMPM is solvable in O(|A|6|A p |2) time when the pattern is \(\{<,\between\}\)-structured, i.e., when each two arcs in the pattern are disjoint or crossing. Our algorithm extends to other closely related models. In particular, it answers an open question raised by Vialette that, rephrased in terms of contact maps, asked whether CMPM for \(\{<,\between\}\)-structured patterns is NP-hard or solvable in polynomial time. Our result stands in sharp contrast to the NP-hardness of closely related problems. We provide experimental results which show that contact maps derived from real protein structures can be processed efficiently.
Quantum tori, mirror symmetry and deformation theory

We suggest to compactify the universal covering of the moduli space of complex structures by noncommutative spaces. The latter are described by certain categories of sheaves with connections which are flat along foliations. In the case of Abelian varieties, this approach gives quantum tori as a noncommutative boundary of the moduli space. Relations to mirror symmetry, modular forms and deformation theory are discussed.
Automatic Image Registration for MR and Ultrasound Cardiac Images

The Statistics Based Image Registration (SBR) method for automatic image registration is presented with application to magnetic resonance (MR)and ultrasound (US) cardiac time series images. SBR is demonstrated for MR myocardial perfusion assessment and US myocardial kinetics studies. The utility of the method for a range of other clinical applications is discussed.
Use of Penalties and Rewards in Agri-Environmental Policy

Achieving high compliance rates in incentive-based agri-environmental schemes is an important issue. This paper explores the use of a m ixed penalty-reward approach under heterogeneous compliance costs. Specifically, we ex amine the use of a “compliance reward” under asymmetric information and output price uncertainty. Using a budget-neutral approach, three possible sources of financing are considered: 1. funds obtained by reducing monitoring effort; 2. the proc eeds of fines collected from participating farmers who are inspected and found n ot to be in compliance; and 3. money saved by reducing the number of farmers enrolled. We discuss the advantages and disadvantages of each source of funding and ana lyze them numerically for both risk-neutral and risk-averse farmers. We show that under certain conditions a mixed penalty-reward system can increase the likelihood o f compliance without increasing programme costs. For risk-averse farmers, however, conditions that ensure a positive outcome from compliance rewards become more restrictive. The implications of these findings are outlined for the future design of agri -environmental schemes with reference to cost-share working lands programmes such as EQIP in the United States.
Simplified procedure for estimating dam and embankment earthquake-induced deformations

The method uses the concept of yield acceleration but is based on the evaluation of the dynamic response of the embankment rather than a rigid body behavior. The yield accelerations, for a potential sliding mass, is estimated on the basis of the static undrained shear strength (with some reduction due to effects of cycling) using pseudostatic methods of stability analysis. The permanent deformations are estimated by numerical double integration of the time history of induced accelerations for various depths of the potential sliding mass. Design curves are presented that were developed on the basis of finite element response computations of embankments subjected to base accelerations representing earthquakes of magnitudes ranging between 6-½ and 8-¼. The simplified procedure is illustrated by an example computation. The permanent deformations are estimated for a 135-ft (40-m) high sandy clay embankment that was shaken by a magnitude 8-¼ earthquake and the results are compared with the observed field behavior.
The Linking of Collective Decisions and Efficiency

For groups that must make several decisions of similar form, we define a simple and general mechanism that is designed to promote social efficiency. The mechanism links the various decisions by forcing agents to budget their representations of preferences so that the frequency of preferences across problems conforms to the underlying distribution of preferences. We show that as the mechanism operates over a growing number decisions, the welfare costs of incentive constraints completely disappear. In addition, as the number of decisions being linked grows, a truthful strategy is increasingly successful and secures the efficient utility level for an agent.
Expert Opinion and the Demand for Experience Goods: An Experimental Approach in the Retail Wine Market

Abstract The effect of expert opinion on demand for experience goods is difficult to quantify, as the relationship between purchases and reviews may be driven by product quality. Further, it is unclear whether a review-based demand effect is due to providing quality or existence information. Using a retail field experiment to overcome these obstacles, we find a significant positive average consumer response to expert opinion labels for wine. Demand decreases for low-scoring wines and increases for wines scoring average or higher. Results indicate that expert opinion labels transmit quality information as opposed to solely shelf visibility.
Conquering the Needle-in-a-Haystack: How Correlated Input Variables Beneficially Alter the Fitness Landscape for Neural Networks

Evolutionary algorithms such as genetic programming and grammatical evolution have been used for simultaneously optimizing network architecture, variable selection, and weights for artificial neural networks. Using an evolutionary algorithm to perform variable selection while searching for non-linear interactions is akin to searching for a needle in a haystack. There is, however, a considerable amount of correlation among variables in biological datasets, such as in microarray or genetic studies. Using the XOR problem, we show that correlation between non-functional and functional variables alters the variable selection fitness landscape by broadening the fitness peak over a wider range of potential input variables. Furthermore, when sub-optimal weights are used, local optima in the variable selection fitness landscape appear centered on each of the two functional variables. These attributes of the fitness landscape may supply building blocks for evolutionary search procedures, and may provide a rationale for conducting a local search for variable selection.
Poverty, AIDS, and Children's Schooling : A Targeting Dilemma

The authors analyze the relationship between orphan status, household wealth, and child school enrollment using data collected in the 1990s from 28 countries in Sub-Saharan Africa, Latin America, the Caribbean, and one country in Southeast Asia. The findings point to considerable diversity-so much so that generalizations are not possible. While there are some examples of large differentials in enrollment by orphan status, in the majority of cases the orphan enrollment gap is dwarfed by the gap between children from richer and poorer households. In some cases, even non-orphaned children from the top of the wealth distribution have low enrollments, pointing to fundamental issues in the supply or demand for schooling that are a constraint to higher enrollments of all children. The gap in enrollment between female and male orphans is not much different than the gap between girls and boys with living parents, suggesting that female orphans are not disproportionately affected in terms of their enrollment in most countries. These diverse findings demonstrate that the extent to which orphans are under-enrolled relative to other children is country-specific, at least in part because the correlation between orphan status and poverty is not consistent across countries. Social protection and schooling policies need to assess the specific country situation before considering mitigation measures.
LDPC codes for fading channels: two strategies

This paper compares two approaches to reliable communication over fading channels using low-density parity check (LDPC) codes. The particular model considered is the block fading channel with independent channel realizations. The first approach uses a block interleaver to create independent sub-channels that are encoded using irregular LDPC codes with rates specified by the appropriate capacity values; this first approach uses a decision feedback structure wherein decoded data are used as pilots to estimate the channel prior to the next round of decoding. The second approach uses a combined graph describing both the channel and the code to iteratively estimate the channel and decode data. For comparable channels, it is shown that the decision-feedback approach provides better performance when a long delay is acceptable, while the iterative receiver provides better performance when more stringent delay constraints are imposed.
Synchronous and asynchronous auction models for dynamic spectrum access

Recently, there is an urge to allocate chunks of the spectrum to the wireless service providers on a more dynamic basis rather than the current practice of static allocation. This shift in paradigm is a result of many studies that indicate the improper utilization of the spectrum by the service providers due to the static spectrum assignment. Also, the use of the spectrum has been found to be space and time invariant. In this paper, we investigate the dynamic spectrum allocation policy for optimal use of the spectrum band. We propose a dynamic spectrum assignment strategy based on auction theory that captures the conflict of interest between wireless service providers and spectrum owner, both of whom try to maximize their respective benefits. We compare two different allocation strategies – synchronous and asynchronous. It is demonstrated that synchronous strategy outperforms the asynchronous strategy. Through simulation results, we show how the optimal usage of spectrum band is achieved along with the maximized revenue for spectrum owner and higher probability of winning spectrum for the service providers.
Computational complexity reduction for BN2O networks using similarity of states

Although probabilistic inference in a general Bayesian belief network is an NP-hard problem, computation time for inference can be reduced in most practical cases by exploiting domain knowledge and by making approximations in the knowledge representation. In this paper we introduce the property of similarity of states and a new method for approximate knowledge representation and inference which is based on this property. We define two or more states of a node to be similar when the ratio of their probabilities, the likelihood ratio, does not depend on the instantiations of the other nodes in the network. We show that the similarity of states exposes redundancies in the joint probability distribution which can be exploited to reduce the computation time of probabilistic inference in networks with multiple similar states, and that the computational complexity in the networks with exponentially many similar states might be polynomial. We demonstrate our ideas on the example of a BN20 network--a two layer network often used in diagnostic problems--by reducing it to a very close network with mnltiple similar states. We show that the answers to practical queries converge very fast to the answers obtained with the original network. The maximum error is as low as 5% for models that reqnire only 10% of the computation time needed by the original BN20 model.
Incumbents without a Campaign Finance Advantage: Competition and Money in Chile’s Congressional Elections

Research from various countries has shown that incumbents in legislative elections raise and spend more money when they face a tougher contest. A statistical analysis of Chilean candidates’ campaign finance disclosures shows the opposite: an inverse relationship between incumbent spending and electoral competitiveness. This occurs because Chile’s deputies are relatively limited in their influence over policy and pork and because the congressional electoral system makes most competitive contests relevant only to the intra-coalitional balance of power. This account implies that political finance is as much a function of political systems and the supply of contributions as it is candidates’ demand for funds, and motivates several hypotheses about campaign finance in Chile. Among others, the analysis confirms that incumbents and challengers compete on a level playing field, spending similar amounts of campaign finance. The paper also illustrates that incumbents and challengers fare equally well in Chile’s “secret” donation system.
Conformal Field Theory Techniques in Large N Yang-Mills Theory

Following some motivating comments on large N two-dimensional Yang-Mills theory, we discuss techniques for large N group representation theory, using quantum mechanics on the group manifold U(N), its equivalence to a quasirelativistic two-dimensional free fermion theory, and bosonization. As applications, we compute the free energy for two-dimensional Yang-Mills theory on the torus to O(1/N 2), and an interesting approximation to the leading answer for the sphere. We discuss the question of whether the free energy for the torus has R → 1/R invariance.
Computational Mechanics: Pattern and Prediction, Structure and Simplicity

Computational mechanics, an approach to structural complexity, defines a process's causal states and gives a procedure for finding them. We show that the causal-state representation—an ∈-machine—is the minimal one consistent with accurate prediction. We establish several results on ∈-machine optimality and uniqueness and on how ∈-machines compare to alternative representations. Further results relate measures of randomness and structural complexity obtained from ∈-machines to those from ergodic and information theories.
Rapid submarine melting driven by subglacial discharge, LeConte Glacier, Alaska

[1] We show that subglacial freshwater discharge is the principal process driving high rates of submarine melting at tidewater glaciers. This buoyant discharge draws in warm seawater, entraining it in a turbulent upwelling flow along the submarine face that melts glacier ice. To capture the effects of subglacial discharge on submarine melting, we conducted 4 days of hydrographic transects during late summer 2012 at LeConte Glacier, Alaska. A major rainstorm allowed us to document the influence of large changes in subglacial discharge. We found strong submarine melt fluxes that increased from 9.1 ± 1.0 to 16.8 ± 1.3 m d−1 (ice face equivalent frontal ablation) as a result of the rainstorm. With projected continued global warming and increased glacial runoff, our results highlight the direct impact that increases in subglacial discharge will have on tidewater outlet systems. These effects must be considered when modeling glacier response to future warming and increased runoff.
Common Envelope Evolution Redux

Common envelopes form in dynamical time scale mass exchange, when the envelope of a donor star engulfs a much denser companion, and the core of the donor plus the dense companion star spiral inward through this dissipative envelope. As conceived by Paczynski and Ostriker, this process must be responsible for the creation of short-period binaries with degenerate components, and, indeed, it has proven capable of accounting for short-period binaries containing one white dwarf component. However, attempts to reconstruct the evolutionary histories of close double white dwarfs have proven more problematic, and point to the need for enhanced systemic mass loss, either during the close of the first, slow episode of mass transfer that produced the first white dwarf, or during the detached phase preceding the final, common envelope episode. The survival of long-period interacting binaries with massive white dwarfs, such as the recurrent novae T CrB and RS Oph, also presents interpretative difficulties for simple energetic treatments of common envelope evolution. Their existence implies that major terms are missing from usual formulations of the energy budget for common envelope evolution. The most plausible missing energy term is the energy released by recombination in the common envelope, and, indeed, a simple reformulation the energy budget explicitly including recombination resolves this issue.
A History of Corporate Finance

Preface 1. History and the modern theory of finance 2. Medieval and Renaissance origins 3. Corporate finance in an age of global exploration: trading companies and oceanic discovery, 1450-1720 4. The emergence of public markets for investment securities, 1688-1815 5. Finance in an age of canals and railroads, 1775-1900 6. Common stock finance and the rise of managerial capitalism, 1900-1940 7. The financing of center firms, 1940-1973 8. Conglomerates and leveraged buy-out partnerships Appendix one: Finance and informational asymmetries in the ancient world Appendix two: International patterns of corporate governance Epilogue.
Center-based clustering under perturbation stability

Clustering under most popular objective functions is NP-hard, even to approximate well, and so unlikely to be efficiently solvable in the worst case. Recently, Bilu and Linial (2010) [11] suggested an approach aimed at bypassing this computational barrier by using properties of instances one might hope to hold in practice. In particular, they argue that instances in practice should be stable to small perturbations in the metric space and give an efficient algorithm for clustering instances of the Max-Cut problem that are stable to perturbations of size O(n^1^/^2). In addition, they conjecture that instances stable to as little as O(1) perturbations should be solvable in polynomial time. In this paper we prove that this conjecture is true for any center-based clustering objective (such as k-median, k-means, and k-center). Specifically, we show we can efficiently find the optimal clustering assuming only stability to factor-3 perturbations of the underlying metric in spaces without Steiner points, and stability to factor 2+3 perturbations for general metrics. In particular, we show for such instances that the popular Single-Linkage algorithm combined with dynamic programming will find the optimal clustering. We also present NP-hardness results under a weaker but related condition.
About Urban Mega Regions : Knowns and Unknowns

Mega urban regions are not a passing phenomenon. They are likely to persist and to enlarge their economic footprints because they benefit from the advantages of market scale, agglomeration economies, location, and the increasing concentration of talented workers. Metropolitan regions which are polycentric, relatively well managed, and have invested heavily in transport infrastructure are able to contain some of the problems attendant upon a concentration of people and industry. Moreover, with energy and water resources becoming relatively scarce and many countries anxious to preserve arable land for farming, the economic advantages of densely populated urban areas are on the rise because they have a lower resource utilization quotient. During the next 15 years, mega urban economies could coalesce in three Southeast Asian locations: Bangkok, Jakarta, and the Singapore-Iskander Development Region (IDR, South Johor). The Bangkok and Jakarta (Jabotabek) metropolitan regions have passed the threshold at least in terms of population size but they have yet to approach the industrial diversity, dynamism, and growth rates of a Shanghai or a Shenzhen-Hong Kong region. Singapore, if coupled with IDR, has the potential but it is still far from being an integrated urban region. This paper examines the gains from closer economic integration and the issues to be settled before it could occur. The paper notes that a tightening of localized economic links between two sovereign nations through the formation of an urban region would involve a readiness to make long-term political commitments based on a widely perceived sense of substantial spillovers and equitably shared benefits. Delineating these benefits convincingly will be essential to winning political support and a precondition for a successful economic flowering.