cssi/SciSciGPT-SciSciNet huggingface dataset:
Towards a Framework for Socially Influencing Systems: Meta-analysis of Four PLS-SEM Based Studies

People continuously experience various types of engagement through social media, mobile interaction, location-based applications, and other technologically advanced environments. Often, integral parts of such socio-technical contexts often are information systems designed to change behaviors and attitudes of their users by leveraging powers of social influence, further defined as socially influencing systems (SIS). Drawing upon socio-psychological theories, this paper initially reviews and presents a typology of relevant social influence aspects. Following that, it analyzes four partial least squares structural equation modeling (PLS-SEM) based empirical studies to examine the interconnectedness of their social influence aspects. As a result, the analysis provides grounds for seminal steps towards the development and advancement of a framework for designing and evaluating socially influencing systems. The main findings can also deepen understanding of how to effectively harness social influence for enhanced user engagement in socio-technical environments and guide persuasive engineering of future socially influencing systems.
Network granger causality with inherent grouping structure

The problem of estimating high-dimensional network models arises naturally in the analysis of many biological and socio-economic systems. In this work, we aim to learn a network structure from temporal panel data, employing the framework of Granger causal models under the assumptions of sparsity of its edges and inherent grouping structure among its nodes. To that end, we introduce a group lasso regression regularization framework, and also examine a thresholded variant to address the issue of group misspecification. Further, the norm consistency and variable selection consistency of the estimates are established, the latter under the novel concept of direction consistency. The performance of the proposed methodology is assessed through an extensive set of simulation studies and comparisons with existing techniques. The study is illustrated on two motivating examples coming from functional genomics and financial econometrics.
Relaxed uncertainty relations and information processing

We consider a range of "theories" that violate the uncertainty relation for anti-commutingobservables derived in [JMP, 49, 062105 (2008)]. We first show that Tsirelson's boundfor the CHSH inequality can be derived from this uncertainty relation, and that relaxingthis relation allows for non-local correlations that are stronger than what can be obtainedin quantum mechanics. We continue to construct a hierarchy of related non-signalingtheories, and show that on one hand they admit superstrong random access encodingsand exponential savings for a particular communication problem, while on the other handit becomes much harder in these theories to learn a state. We show that the existence ofthese effects stems from the absence of certain constraints on the expectation values ofcommuting measurements from our non-signaling theories that are present in quantumtheory.
Effects of Criminal Procedure on Crime Rates: Mapping Out the Consequences of the Exclusionary Rule*

Abstract In 1961, in its Mapp v. Ohio ruling, the Supreme Court required every state to exclude from criminal trials evidence obtained in violation of the Fourth Amendment. This is the “exclusionary rule.” At the time the Supreme Court issued its ruling, 24 states allowed ill‐gotten evidence in their criminal trials, and 24 excluded it. An economic analysis of the search warrant process predicts an increase in crime rates after the Supreme Court forced states to adopt the exclusionary rule as police officers substitute away from searches toward alternatives they consider less effective. Our empirical analysis supports this theoretical prediction. We find a statistically and economically significant increase in crimes followed the Supreme Court’s imposition of the exclusionary rule, with suburban cities bearing the brunt of the Supreme Court's decision.
An Experimental Test of a General Class of Utility Models: Evidence for Context Dependency

Generic utility theory, a general axiomatization of utility principles developed by Miyamoto (1988, 1992), is discussed as a formulation that captures a large class of utility theories. Several general mathematical functions were used to specify further the scaling of utility within this class of models. The scaling parameters in the generic utility representation should remain invariant across gambling contexts, and this predicted invariance provided a means for testing the theory. Evidence is presented that the prediction of scaling-parameter invariance is violated. This failure is interpreted as a consequence of employing an absolute reference system for a problem that is context-sensitive.
Fairness judgments and counterfactual thinking: pricing goods versus services

Purpose – This paper aims to propose and empirically document the idea that people’s perceptions of having been treated fairly depend, in part, on whether the explanation provided to them of a product’s pricing is primarily based on the costs of labor (a service) versus materials (goods). Because materials are more fixed and tangible than the effort of labor, it is argued that people will have fewer counterfactual thoughts about how things could have been different with the cost of materials than those associated with labor. This has implications for fairness judgments more generally, as it suggests that people may be uneven in which types of data they attend to when making fairness judgments. Three experiments are presented that empirically test the relationship between the salience of goods versus services in the price paid and the resulting perceptions of fairness. Findings confirm that thoughts of money spent on a service were associated with lesser feelings of fairness than were thoughts of money spe...
An Analysis of the Potential Economic Impact of Huanglongbing on the California Citrus Industry

The disease Huanglongbing (HLB) was first discovered in the United States in 2005, in a Florida commercial citrus grove. Since its discovery, HLB has not only decreased citrus production, but has drastically increased production costs. With California contributing over 80% of the nation’s fresh oranges, it is important to attempt to keep HLB from becoming endemic in this state. In this study, two alternative management practices are examined to estimate the potential total loss in production value due to HLB on the California citrus industry over a 20 year period. The total loss is estimated to be $2.7 billion under a do-nothing approach and $2.2 billion under an aggressive action approach. Limiting the spread of HLB is the preferred approach. It not only results in total damage savings of $2,803 per acre over the do-nothing approach, but also protects the California citrus industry from HLB and promotes economic growth.
Path planning using a potential field representation

The findpath problem is the problem of moving an object to the desired position and orientation while avoiding obstacles. The authors present an approach to this problem using a potential-field representation of obstacles. A potential function similar to an electrostatic potential is assigned to each obstacle, and the topological structure of the free space is derived in the form of minimum potential valleys. A path specified by a subset of valley segments and associated object orientations, which minimizes a heuristic estimate of path length and the chance of collision, is selected as the initial guess of the solution. Then, the selected path as well as the orientation of the moving object along the path is modified to minimize a defined cost of the path. Findpath problems possessing three different levels of difficulty are identified. Path optimization is performed in up to three stages, according to the level of difficulty of the problem. These three stages are addressed by three separate algorithms which are automatically selected. The performance of the algorithms is illustrated. >
The Colonial Origins of Comparative Development: An Investigation of the Settler Mortality Data

In a seminal contribution, Acemoglu, Johnson, and Robinson (2001) evaluate the effect of property rights institutions on national income using estimated mortality rates of early European settlers as an instrument for the risk of capital expropriation. Returning to their original sources, I find the settler mortality data suffer from a number of inconsistencies, comparability problems, and questionable geographic assignments. When various methods are used to deal with these issues, the first-stage relationship between mortality and expropriation risk is no longer robust and typically insignificant. Consequently instrumental variable estimates are unreliable and suffer from weak instrument pathologies.
Does Wal-Mart Cause an Increase in Anti-Poverty Program Expenditures?

As the largest private sector employer in the United States, Wal-Mart experiences considerable scrutiny over its influence on a number of regional fiscal and economic issues. These include its impact on the local retail market structure, land use patterns, local fiscal conditions and general business practices. Criticism of Wal-Mart’s business practices include, but are not limited to its anti-unionization efforts, sale of imported goods, wage and compensation structure and the use of Federal and state anti-poverty transfers by its employees. In this paper I evaluate the concerns regarding the role of Wal-Mart in changing expenditures on Federal and state anti-poverty transfers in the United States. Using a panel of the conterminous 48 states, correcting for time and spatial autocorrelation and local government mix and policy changes, I find the number of Wal-Marts, and their employment share in the retail sector have no impact on Foodstamps expenditures. Expenditures on AFDC/TANF are unaffected by Wal-Mart in the test using the number of stores to represent Wal-Mart’s presence. In the retail employment share, the impact is negative, with a 1 percent increase in Wal-Mart’s share reduced AFDC/TANF expenditures by 3.3 percent. I find that Wal-Mart does increase Medicaid expenditures by roughly $898 per worker, which is consistent with other studies of the Medicaid costs per low wage worker across the United States.
Diversity and Optimality

In this paper, we construct a general model of diverse problem solvers of limited abilities. We use this model to derive two main results: (1) a collection of diverse, bounded problem solvers can locate optimal solutions to difficult problems and (2) a collection of problem solvers of diverse abilities tends to jointly outperform a collection of high ability problem solvers, where a problem solver's ability equals her expected individual problem. Submitted to: American Economic Review.
Value of Beef Steak Branding: Hedonic Analysis of Retail Scanner Data

Consumers rely on experience and credence attributes when purchasing beef from retailers. It is essential for all beef industry sectors to recognize the complexity of consumer buying behavior. A hedonic model is estimated to determine if there are incentives to brand beef steaks, the types of brands that entertain price premiums, and the level of existing premiums. Most branded steaks garnered premiums along with organic claims, religious processing claims, and premium cuts. Factors influencing brand value were new brands targeting emerging consumer trends, brands with regional prominence, and brands positioned as special label, program/breed specific production, and store labels.
Household Income, Termination Risk and Mortgage Pricing

The premium embedded in home mortgage loans to compensate investors for their exposure to prepayment risk is a significant component of the cost of home mortgage lending. Moreover, there is some reason to believe that prepayment risk may be lower for loans to lower-income housing borrowers, especially those that are first-time home owners. If so, investor recognition of this advantage should facilitate greater willingness to acquire portfolios of lower-income housing loans, and encourage more competitive pricing in this segment of the market. This study investigates the possibility of differential mortgage prepayment behavior between lower-income home owners and non-low income home owners. The investigation relies on samples of the American Housing Survey spanning ten years of experience from 1985 to 1995. We find no significant difference between the termination or refinancing behavior of non-low income and low-income households. This result is robust to a number of alternative specifications such as restricting the low-income test group to non-moving households and to first-time owners. The same conclusions are derived from both aggregate prepayment rates and from analysis of individual household prepayment behavior.
An architecture for chip-to-chip communications on network line cards

In this paper, we propose a 3D bus architecture as a processor-memory interconnection system to increase the throughput of the memory system currently used on line cards. The main advantage of the proposed architecture is to increase the network processor off-chip memory bandwidth while diminishing the latency otherwise caused by the single bus competition.
The estimation of the WCET in super-scalar real-time system

Predicting and estimating the execution time of a program is of the utmost importance to designers of real-time systems, particularly hard real-time systems. This paper describes an algorithm for estimating an improved WCET (worst-case execution time) of a real-time program that utilizes a path generating approach to factor into the calculation the effects of super-scalar processor pipelining. The algorithm starts by determining the program's control flow. The pipelining analysis takes into account the simultaneous execution of instructions in distinct blocks in two separate pipelines. The timing tool uses the pipelining analysis to estimate the WCET. The results indicate that this method enhances the acquisition of tighter estimates.
Accounting Standards and Financial Market Stability: An Experimental Examination

We examine the effects of three alternative accounting methods in an experimental asset market characterised by bubbles and crashes: fair value (M2M), historical cost (HC) and marked to fundamental value (M2F). Each treatment is replicated under both no‐leverage and leverage conditions. In the no‐leverage condition, we find that accounting methods do not have a significant effect on asset mispricing. In the leverage condition, both M2M and M2F accounting methods exacerbate asset mispricing. Yet, the two differ in leverage dynamics. M2F markets are completely immune to defaults, while M2M markets experience the most frequent and the most severe defaults.
An evaluation of deep soil configurations in the CLM3 for improved representation of permafrost

[1] A thin layer of soil used in many coupled global climate models does not resolve the heat reservoir represented by underlying ground material. Under representation of this feature leads to unrealistic simulation of temperature dynamics in the active layer and permafrost. Using the Community Land Model (CLM3) and its modifications we estimate a required thickness of soil layers to calculate temperature dynamics within certain errors. Our results show that to compute the annual cycle of temperature dynamics for cold permafrost, the soil thickness should be at least 30 meters. Decadal-to-century time scales require significantly deeper soil layers, e.g. hundreds of meters. We also tested a new geometrical configuration of the soil layer geometry which is called slab permafrost. This configuration is represented by a thick soil layer underneath the traditional resolved soil layer. The model configuration with 30 m deep resolved soil layer and a 30 to 100 m thick slab shows results that favorably compare with our benchmark model which has a fully resolved 300 m-deep soil layer.
Stability and Performance of High Emissivity Coatings for Radiation Coupled Thermionic Converters

The use of high emissivity coatings is being investigated in order to reduce the required operating temperatures of radiation coupled thermionic converters. Testing was undertaken to evaluate the performance and stabilityof two candidate high emissivity coatings on two different substrate materials. Hafnium carbide (HfC) and hafnium oxide (HfO 2 ) were plasma sprayed onto tungsten (W) and rhenium (Re) substrates. Baseline 'as-sprayed' samples were taken and the remaining portions were aged in vacuum at approximately 2000 °C for approximately 150 h. Samples were sectioned, mounted and polished for scanning electron microscopic (SEM) inspection both before and after aging. Results of the SEM and energy dispersive spectrometry (EDS) evaluations showed interdiffusion of the coating and the substrate for the HfC samples. Interdiffusion was not evident on the HfO 2 samples. Spectral hemispherical surface reflectance measurements were made over a range of 2 μm to 25 μm on samples prior to and after aging in order to evaluate changes in the surface emissivity. The emissivity decreased significantly for the HfC samples and only slightly for the HfO 2 as a result of the aging.
Explosion Phenomenology in Jointed Rocks: New Insights

This article deals with the effects of high-explosive and nuclear explosions in rock masses. We first highlight the strong influence of geological discontinuities, such as joints and faults, on ground motion characteristics. Then, we briefly introduce the Discrete Element method, as a new technique for numerical simulations. It is shown to be far superior to continuum-based approaches, when dealing with the dynamics of discontinuous media such as jointed rocks. Finally, we simulate the ground effects from a generic contained nuclear explosion, which bears some similarity to the SHOAL event in granite. This calculation is intended to emphasize the influence of the near-source geology on the distribution of energy, and on the motion at various azimuths in the medium. 17 refs., 10 figs.
Fairtrade and market failures in agricultural commodity markets

This paper concerns an NGO intervention in agricultural commodity markets known as Fairtrade. Fairtrade pays producers a minimum unit price and provides capacity building support to member cooperative organizations. Fairtrade's organizational capacity support targets those factors believed to reduce the commodity producer's share of returns. Specifically, Fairtrade justifies its intervention in markets like coffee by claiming that market power and a lack of capacity in producer organizations 'marks down' the prices producers receive. As the market share of Fairtrade coffee grows in importance, its intervention in commodity markets is of increasing interest. Using an original data set collected from fieldwork in Costa Rica, this paper assesses the role of Fairtrade in overcoming the market factors it claims limits producer returns. Features of the Costa Rican input market for coffee permit a generalization of the results. The empirical results find that market power is a limiting factor in the Costa Rican market and that Fairtrade does improve the efficiency of cooperatives, thereby increasing the returns to producers. These results do not depend on the minimum price policy of Fairtrade and therefore can inform on its organizational support activities. Finally, the results also suggest that producers selling to vertically integrated, multinational coffee mills face lower producer price 'mark-downs' compared with domestically owned non-cooperative mills. This result contradicts the popular view that the increasing concentration of vertically integrated multinational firms accounts for a decline in producers' share of coffee returns.
Macroeconomic Models and the Determination of Crowding Out

The importance of crowding out has been an ongoing question in the Economics literature for many years. Some economists believe that deficits replace private spending while other economists feel that most of this crowding out is offset by Ricardian equivalence. In an attempt to resolve this controversy, many economists have formulated macroeconomic models and have used these models to empirically test the notion of crowding out. This paper revisits this methodology. It examines four useful macroeconomic models and shows the relationship between the model assumed, the empirical results obtained and the conclusions concerning crowding out. We demonstrate that the same empirical results may be obtained from different models, but can yield very different conclusions concerning crowding out. It is concluded that the answer to this controversy involves, in part, a more complete understanding of the structural foundations of the macroeconomic models being tested.
New Daily Persistent Headache

Primary new daily persistent headache is a rare disorder of children and adults defined by the onset of daily and unremitting headaches within 3 days of onset lasting 4 hours or more daily. There may be a link between a preceding flu-like or upper respiratory infection in about 15%, a stressful life event in 10%, or extracranial surgery in 10%. Migraine symptoms may be present in over 50%. The headache is generalized in most but may be unilateral in 11% and may be localized to any head region. The diagnosis is one of exclusion as many secondary etiologies can cause similar headaches. The pathophysiology of the primary type is unknown. There are no prospective placebo controlled trials of preventive treatment so prevention is empiric using the same medications for the phenotype of chronic migraine or tension-type headache. Most patients have persistent headaches, although about 15% will remit, and 8% will have a relapsing-remitting type.
Extending a Multidatabase Manipulation Language to Resolve Schema and Data Conflicts

The management of Multidatabase Systems (MDBS) is complicated by possible structural and semantic heterogeneity of the member database systems, and the requirements to preserve their local autonomy. Semantic heterogeneity is concerned with the differences in the meaning and interpretation of similar data objects across the different systems. In loosely coupled database federations, static schema integration may be not feasible and heterogeneity conflicts must be dealt with at the application level. Therefore, a multi-database access language must be equipped accordingly with special features to resolve structural and semantic discrepancies.
Cluster-Robust Bootstrap Inference in Quantile Regression Models

ABSTRACTIn this article I develop a wild bootstrap procedure for cluster-robust inference in linear quantile regression models. I show that the bootstrap leads to asymptotically valid inference on the entire quantile regression process in a setting with a large number of small, heterogeneous clusters and provides consistent estimates of the asymptotic covariance function of that process. The proposed bootstrap procedure is easy to implement and performs well even when the number of clusters is much smaller than the sample size. An application to Project STAR data is provided. Supplementary materials for this article are available online.
Aspects of Relativistic Sum Rules

Abstract The status of our understanding of relativistic sum rules is reviewed. The recent development of new theoretical methods for the evaluation of these sum rules offers hope for further advances in this challenging field. These new techniques are described, along with a discussion of the source of difficulties inherent in such relativistic calculations. A connection is pointed out between certain sum rules for atomic interactions with charged particles and those for interactions with photons.
Blue Supergiants as a Tool for Extragalactic Distances — Empirical Diagnostics

Blue supergiant stars can be exceptionally bright objects in the optical, making them prime targets for the determination of extragalactic distances. I describe how their photometric and spectroscopic properties can be calibrated to provide a measurement of their luminosity. I first review two well-known techniques, the luminosity of the brightest blue supergiants and, with the aid of recent spectroscopic data, the equivalent width of the Balmer lines. Next I discuss some recent developments concerning the luminosity dependence of the wind momentum and of the flux-weighted gravity, which can provide, if properly calibrated, powerful diagnostics for the determination of the distance to the parent galaxies.
Using an Interest Ontology for Improved Support in Rule Mining

This paper describes the use of a concept hierarchy for improving the results of association rule mining. Given a large set of tuples with demographic information and personal interest information, association rules can be derived, that associate ages and gender with interests. However, there are two problems. Some data sets are too sparse for coming up with rules with high support. Secondly, some data sets with abstract interests do not represent the actual interests well. To overcome these problems, we are preprocessing the data tuples using an ontology of interests. Thus, interests within tuples that are very specific are replaced by more general interests retrieved from the interest ontology. This results in many more tuples at a more general level. Feeding those tuples to an association rule miner results in rules that have better support and that better represent the reality.
Galaxies at High Redshift

Within just the last few years, we have advanced from knowing only a few galaxies at z > 2 to having redshifts for nearly 1000 z ∼ 2 – 5 objects. The majority of this sample has been detected through the photometric ‘drop-out’ technique used so successfully by Steidel and his collaborators. In addition, a handful of objects have already been detected at z > 5, and we may already have a few objects at z > 6! These data, plus that at z > 2 have resulted in a characterization of the star formation history of the universe, commonly known as the ‘Madau plot’, which gives SFR per comoving volume vs. redshift from the present day at z = 0 to z ∼ 5. Recently, we have realized that dust has significantly affected our SFR estimates for the objects that have been detected in the optical, and have developed approaches to correct for that extinction. We now also have increasingly good evidence that a substantial fraction (> 50%?) of the high redshift star formation occurs in dust-enshrouded starbursts that were detected at 850 pm with a submm bolometer SCUBA on the JCMT telescope. These objects will typically be too faint to detect and measure redshifts in the optical, though those that can have already provided valuable constraints. The highest redshift objects at z ∼ 5 and beyond are intriguing sources, but test even the limits of Keck and of HST. The detailed study of such sources may well only be practical for gravitationally-lensed objects, where the high magnification allows for a much more detailed study of the proto-galaxy’s structure, until even larger space-based (NGST) and ground-based (30-m plus) telescopes are developed.
Cases Relating to Chapter 16 – Evidence Unconstitutionally Obtained

Publisher Summary This chapter presents several case studies related to evidence obtained unconstitutionally. These cases include the case of United States versus Leon, Arizona versus Gant, Georgia versus Randolph, and Horton versus California. The first case presents the question whether the Fourth Amendment exclusionary rule should be modified so as not to bar the use in the prosecution's case in chief of evidence obtained by officers acting in reasonable reliance on a search warrant issued by a detached and neutral magistrate but ultimately found to be unsupported by probable cause. In the second case Gant was charged with possession of a narcotic drug for sale and possession of drug paraphernalia. Gant filed a motion to suppress the evidence taken from the car on the theory that the police could not have reasonably believed that Gant could have any access to gun or cocaine since he was handcuffed in a cruiser and secondarily, police could not have discovered any evidence inside the automobile to support the driving under a suspension charge. The third case focuses on the valid warrantless entry and search of premises when police obtain the voluntary consent of an occupant who shares, or is reasonably believed to share, authority over the area in common with a co-occupant who later objects to the use of evidence so obtained.
Retrospective on quantization

Quantization is still a central problem of modern physics. One example of an unsolved problem is the quantization of Nambu mechanics. After a brief comment on the role of Harrison cohomology, this review concentrates on the central problem of quantization of QCD and, more generally, quark confinement seen as a problem of quantization. Several suggestions are made, some of them rather extravagant.
Morbidity associated with induction of labor.

Hamblenl states that we do not know why labor begins. Reynolds2 believes that the onset of labor is due to alterations in estrogen-pituitary-progestin balance influenced by uterine distention. The most helpful work comes from Lyon3 in his search to find changes concurrent with the initiation of labor. By using the new glucuronic acid method, the NaPG excretion in the urine decreases preceding the onset of labor similarly in those cases at term, postmature, and in premature groups. There is a positive correlation between an extensive fall of conjugated pregnandiol and the onset of labor. Also, there is strong evidence of a marked drop in available progesterone preceding the onset of normal labor. With this new knowledge available, a different interpretation may be placed on studies of induced labor. Lyon3 shows there is a 58 per cent decrease of sodium pregnandiol glucuronidate excretion in the urine during the four days before delivery takes place. The greatest changes take place within the 48 hours to 72 hours preceding termination of the third stage of labor. Morton* of Lynch’s Clinic reports induction of labor by means of artificial rupture of the membranes, castor oil and quinine, and nasal pituitrin. Guttmaeher, in 1931, and Slemons,g in 1932, report further on induction of labor by means of artificial rupture of the membranes, showing that the latent period and duration of labor are shorter whenever the cervix is dilated, and naturally effaced at the time the membranes are ruptured artificially for ind.uction of labor. Stern7 Plass,s and Mathieu and Holmang all show the low morbidity and excellent results obtained by induction. It must be remembered, however, that their material was selected from abundance and that their skill and working conditions were of the best.
Evaluating Asset Pricing Implications of DSGE Models

This paper conducts an econometric evaluation of structural macroeconomic asset pricing models. A one-sector dynamic stochastic general equilibrium model (DSGE) with habit formation and capital adjustment costs is considered. Based on the log-linearized DSGE model, a Gaussian probability model for the joint distribution of aggregate consumption, investment, and a vector of asset returns R(t) is specified. We facilitate the stochastic discount factor M(t) representation obtained from the DSGE model and impose the no-arbitrage condition E[M(t)R(t)|t-1]=1. In addition to the full general equilibrium model, we also consider consumption and production based partial equilibrium specifications, and a more general reference model. To evaluate the various asset pricing models we compute posterior model probabilities and loss function based measures of model adequacy.
On the complexity of optimal routing and content caching in heterogeneous networks

We investigate the problem of optimal request routing and content caching in a heterogeneous network supporting in-network content caching with the goal of minimizing average content access delay. Here, content can either be accessed directly from a back-end server (where content resides permanently) or be obtained from one of multiple in-network caches. To access a piece of content, a user must decide whether to route its request to a cache or to the back-end server. Additionally, caches must decide which content to cache. We investigate the problem complexity of two problem formulations, where the direct path to the back-end server is modeled as i) a congestion-sensitive or ii) a congestion-insensitive path, reflecting whether or not the delay of the uncached path to the back-end server depends on the user request load, respectively. We show that the problem is NP-complete in both cases. We prove that under the congestion-insensitive model the problem can be solved optimally in polynomial time if each piece of content is requested by only one user, or when there are at most two caches in the network. We also identify a structural property of the user-cache graph that potentially makes the problem NP-complete. For the congestion-sensitive model, we prove that the problem remains NP-complete even if there is only one cache in the network and each content is requested by only one user. We show that approximate solutions can be found for both models within a (1 − 1/e) factor of the optimal solution, and demonstrate a greedy algorithm that is found to be within 1% of optimal for small problem sizes. Through trace-driven simulations we evaluate the performance of our greedy algorithms, which show up to a 50% reduction in average delay over solutions based on LRU content caching.
Detection, classification, and collaborative tracking of multiple targets using video sensors

The study of collaborative, distributed, real-time sensor networks is an emerging research area. Such networks are expected to play an essential role in a number of applications such as, surveillance and tracking of vehicles in the battlefield of the future. This paper proposes an approach to detect and classify multiple targets, and collaboratively track their position and velocity utilizing video cameras. Arbitrarily placed cameras collaboratively perform self-calibration and provide complete battlefield coverage. If some of the cameras are equipped with a GPS system, they are able to metrically reconstruct the scene and determine the absolute coordinates of the tracked targets. A background subtraction scheme combined with a Markov random field based approach is used to detect the target even when it becomes stationary. Targets are continuously tracked using a distributed Kalman filter approach. As the targets move the coverage is handed over to the "best" neighboring cluster of sensors. This paper demonstrates the potential for the development of distributed optical sensor networks and addresses problems and tradeoffs associated with this particular implementation.
AN INTRODUCTION TO ANOMALIES

These lectures are dedicated to the study of the recent progress and implications of anomalies in quantum field theory. In this introduction we would like to recapitulate some of the highlights in the history of the subject. In its original form,1 one considers a triangle diagram with two vector currents and an axial vector current. Requiring Bose symmetry and vector current conservation in the vector channels, one finds that the axial vector current is not conserved, leading to the breakdown of chiral symmetry in the presence of external gauge fields. The existence of this anomaly led to an understanding of π0 decay, and later on to the resolution of the U(1) problem2 in QCD. These anomalies correspond to the breakdown of global axial symmetries, and their existence does not jeopardize unitarity or renormalizability. More dangerous anomalies appear whenever chiral currents are coupled to gauge fields. For example, in four dimensions we can consider V-A currents coupled to gauge fields as in the standard Weinberg-Salam model, and compute the same triangle diagram with V-A currents on each vertex.3 Again one finds an anomaly, and unless the anomaly cancels after summing over all the fermion species, the theory will not be gauge invariant, implying a loss of renormalizability. If we recall the Feynman rules for non-Abelian gauge theories coupled to fermions in some representation Ta of the gauge group G, the anomaly for gauge currents is proportional to a purely group theoretic factor times a Feynman integral.
EFFECTS OF WAVES ON THE BOUNDARY LAYER OF A SURFACE-PIERCING BODY

The boundary layer development upon a body that intersects a free surface can be greatly influenced by the presence of free-surface gravity waves. In particular, waves of sufficient steepness induce, near the free surface, a region of flow separation that is otherwise absent. This significantly modifies both the viscous and wave- resistance components, making this a problem of considerable engineering importance. In spite of this, very little detailed experimental or rigorous theoretical work has been done on the problem, according to the author. In this exposition he describes investigations he carried out to fill that gap in knowledge.
Topographic mapping of paterae and layered plains on Io using photoclinometry

We have generated regional scale photoclinometry digital elevation models (DEMs) from Voyager and Galileo imagery of Io that resolve small-scale topographic features including paterae and layered plains. Given the difficulty of applying this technique to Io due to its anomalous surface albedo properties, we have experimented extensively with the relevant procedures in order to generate what we consider to be the most reliable DEMs. The DEMs have been used to gauge the depths of 23 paterae and the heights of 12 layered plains outcrops, and we find the very similar relief and frequent close association of the two landforms to support the existence of a mixed silicate-volatile layer covering much of the surface of Io.
Can conditional cash transfer programs play a greater role in reducing child undernutrition

The paper attempts to answer the following questions: how can conditional cash transfer (CCTs) be better designed, coordinated, and leveraged to increase their impact on child undernutrition? How can best practices from nutrition interventions be applied to ensure maximum CCT impact on child undernutrition? What are the key issues affecting the potential for CCTs to become an effective tool in nutrition policy and programming? The paper is organized as follows: section two defines undernutrition and discusses the magnitude of the problem, implications for long-term human capital development, and how and when to intervene. Section three describes CCT programs, including conceptual foundations for applying conditionality's, the position of CCTs in the current development paradigm, and reasons for their widespread popularity. Section four develops a rationale for using CCTs as one of a set of tools to improve nutritional status. Section five compares the design, implementation, and impacts of CCTs in five Latin American countries (Brazil, Colombia, Honduras, Nicaragua, and Mexico). Section six explores how best practices in nutrition could inform CCT design and section seven introduces redesigned and emerging CCTs focusing on nutrition. Section eight examines some of the key issues surrounding the use of CCTs for nutrition policy, including program eligibility and benefit duration, the use of conditionality's, supply-side investments, the cost and cost effectiveness of these efforts, and institutional roles and coordination. Section nine concludes with recommendations and suggestions for further research.
Chern classes for singular hypersurfaces

We prove a formula expressing the Chern-Schwartz-MacPherson class of a hypersurface in a nonsingular variety as a variation on another definition of the homology Chern class of singular varieties, introduced by W. Fulton; and we discuss the relation between these classes and others, such as Mather's Chern class and the ,l-class we introduced in previous work. 0. INTRODUCTION There are several candidates for a notion of homology 'Chern class' of a (possibly singular) algebraic variety X, agreeing with the class obtained as dual of the total Chern class of the tangent bundle of X if X is nonsingular. One such notion was introduced by R. MacPherson [MacPherson], agreeing (as it was later understood) with a class introduced earlier by M.-IJ. Schwartz, and enjoying good functorial properties. A different class was defined by W. Fulton ([Fulton], 4.2.6), in a different and somewhat more general setting. The main purpose of this paper is to prove a precise relation between the Schwartz-MacPherson and the Fulton class of a hypersurface X of a nonsingular variety. We denote these two classes by csM(X), CF (X) respectively. A summary of the context and essential definitions is given in ?1, where we present several different statements of the result. The version which expresses most directly the link between the two classes mentioned above goes as follows. Fulton's class for a subscheme X of a nonsingular variety M is defined by CF(X) :m= c(TMIx) n s(X, M), that is, by capping the total Chern class of the ambient space against the Segre class of the subscheme (it is proved in [Fulton], 4.2.6 that this definition does not depend on the choice of the ambient variety M). For a hypersurface X of a nonsingular variety M, let Y be the 'singular subscheme' of X (locally defined by the partial derivatives of an equation of X). For an integer k > 0 we can consider the k-th thickening X(k) of X along Y, and then consider its Fulton class CF(X(k)). It is easily seen that CF (X(k)) is a polynomial in k (with coefficients in the Chow group A,*(X)), so it can be formally evaluated at negative k's. We can then define a class (* C*(X) :_ CF(X( 1))The main result of this paper is Theorem. c* (X) is equal to the Chern-Schwartz-MacPherson class of X. Received by the editors June 3, 1997. 1991 Mathematics Subject Classification. Prinmary 14C17, 32S60. Supported in part by NSF grant DMS-9500843. @ 1999 American Mathbemiatical Society 3989 This content downloaded from 157.55.39.136 on Thu, 01 Dec 2016 05:45:16 UTC All use subject to http://about.jstor.org/terms
Marginal and Conditional Distribution Estimation from Double-Sampled Semi-Competing Risks Data

Informative dropout is a vexing problem for any biomedical study. Most existing statistical methods attempt to correct estimation bias related to this phenomenon by specifying unverifiable assumptions about the dropout mechanism. We consider a cohort study in Africa that uses an outreach programme to ascertain the vital status for dropout subjects. These data can be used to identify a number of relevant distributions. However, as only a subset of dropout subjects were followed, vital status ascertainment was incomplete. We use semi-competing risk methods as our analysis framework to address this specific case where the terminal event is incompletely ascertained and consider various procedures for estimating the marginal distribution of dropout and the marginal and conditional distributions of survival. We also consider model selection and estimation efficiency in our setting. Performance of the proposed methods is demonstrated via simulations, asymptotic study and analysis of the study data.
Strategic Communication for Privatization, Public-private Partnerships and Private Participation in Infrastructure Projects

This publication reviews the experiences of the World Bank and its clients in employing public communication programs during the processes of privatization and private sector participation. Drawing from academic and policy research as well as from case studies, it highlights good practices and identifies lessons learned through an examination of successes and failures. This publication also recommends principles of strategic communication and offers a methodology for researching and analyzing the communication issues associated with privatization and private sector participation. It includes an operational approach to design and implementation of public communication programs for the various forms of privatization and public-private initiatives. This publication is divided into two sections. The first section includes examples of privatization efforts, failures and successes, noting the role that was played by communication, or lack thereof. The second section sets out the key concepts and tools that communication specialists bring to privatization programs, along with examples of their effective use in both developed and developing countries.
The World Bank and the provision of assistance to redundant workers : experience with enterprise restructuring and future directions

This paper summarizes the World Bank's experience in dealing with redundant (laid-off) workers. It identifies World Bank lending of 88 loans in 47 countries that have contained labor assistance to redundant workers related to enterprise restructuring or privatization since 1987. The paper classifies total World Bank lending into three broader categories that consist of different forms of labor and income support. The findings show that the total number of such loans more than doubled from 1994-98, and most of Bank's labor assistance goes towards long-term capacity building to develop the institutional framework needed to support redundant workers. Training, labor market mobility and severance pay programs were the three major labor programs used most frequently. The paper examines regional differences in total amount of labor assistance and regional difference in using the particular type of labor assistance. The findings also show how major type of labor assistance program changes over time, for example, severance pay program surpassed training program in 1997.
Integrating housing wealth into the social safety net : the elderly in Moscow

The elderly in Russia have often been among those least able to cope with all the changes that have taken place during the transition. Unlike the situation prior to reform - when pensions were stable - they now face considerable uncertainty. If they have not been in poverty, many have been close to it. While the elderly have experienced difficulties, they have also been the beneficiaries of a very large transfer of wealth. In Russia, as in most transition economies, housing was privatized, under giveaway terms. As a result, although many elderly households have low incomes, based on their wealth, their deprivation would appear to be less serious. Unfortunately, in the absence of a developed financial system, it is difficult to use this wealth without selling it. In Russia, all households, not just the elderly, have not been able to borrow. The existence of such large unencumbered wealth holdings by lower income elderly households creates an opportunity to provide what might be termed "housing safety net insurance" at low public cost. More than reducing the incidence of poverty, such schemes could allow also many of the elderly to be able to move out of poverty and into middle income status. The authors explain why many of the elderly in the former Soviet Union (FSU), not just in Russia, are likely to have so much housing wealth. Then they discuss how financial instruments could access this wealth. The authors also discuss the empirical situation of the elderly in Moscow, illustrating the potential demand for such products. Finally, they suggest that the results for Moscow are likely to be similar in many other FSU countries because these countries also have elderly populations who also own a great deal of unencumbered housing wealth. This paper - a product of the Urban Unit, Transport and Urban Development Department - is part of a larger effort in the department to examine housing and poverty issues.
Guidelines for Extension Program Business Planning

This Note describes ten guidelines for using the program business planning process to achieve a successful transition in a new regional delivery model. The process is simple, practical and feasible.