A Program Behavior Model Based on Event Grammar and its Application for Debugging Automation
- Mikhail Auguston
. The notion of event constitutes the basis of the target program behavior model. This model, called H-space (History-space), is formally defined through a set of axioms (event grammar) for two basic relations, which may hold between two arbitrary events: the events may be sequentially ordered or one of them might be included in another composite event. Target program execution history is represented as a set of nested events. A general paradigm of "computation over execution history" is suggested in this paper as a basis for debugging automation. A language to describe computations over execution histories of target programs provides...
Visualizing Interaction History on a Collaborative Web Server
- Andreas Dieberger; Peter Lönnqvist
A CoWeb is a collaborative Web space that allows people to modify content and create new pages in a very easy fashion. We modified the original CoWeb to visualize interaction history information in an effort to make it a more social space and to allow users to engage in social navigation. KEYWORDS: Social Navigation, History Enriched Environments, Visualizing Interaction Histories INTRODUCTION The CoWeb (for collaborative Web) was implemented by Mark Guzdial (based on earlier work by Ward Cunningham) to support anchored discussions. In a CoWeb everybody can modify every page . After clicking on a link to "modify this page"...
Strategies For Selecting Communication Structures In Cooperative Search
- Shuji Narazaki; Hiroomi Yamamura; Norihiko Yoshida
Modeling environment is essential for agents to cooperate with each other in a distributed system. In this paper, we propose two strategies for selecting agents' communication structures in a cooperative search using their local histories as a model of their computational environment. Under the assumption of homogeneity of agents, an agent can select a proper communication structure by using a history of local computation, and the utility of communication always matches its cost. Simulations using the traveling salesman problem show that strategies produce high performance. We also describe an extension of these strategies to other areas and the means to...
The Practitioner of Science: Everyone her Own Historian
- Mary P. Winsor
Carl Becker's classic 1931 address "Everyman his own historian" holds lessons for historians of science today. Like the professional historians he spoke to, we are content to display the Ivory-Tower Syndrome, writing scholarly treatises only for one another, disdaining both the general reader and our natural readership, scientists. Following his rhetoric, I argue that scientists are well aware of their own historicity, and would be interested in lively and balanced histories of science. It is ironic that the very professionalism that ought to equip us to write such histories has imposed on us a powerful taboo that renders us unable...
A Case Study in Knowledge Acquisition for Insurance Risk Assessment using a KDD Methodology
- Graham J. Williams; Zhexue Huang
We describe some initial experiences in dealing with the task of acquiring knowledge where a very large collection of case histories is available. A Knowledge Discovery in Databases (KDD) approach is taken. KDD is the process of extracting novel information and knowledge from large databases, consisting of many interacting stages performing specific data manipulation and transformation operations with an information flow from one stage onto the next (and usually with feedback into previous stages). We characterise our experiences of this process for the task of acquiring knowledge for the domain of motor vehicle insurance premium setting for NRMA Insurance Limited.
Global Chemical Evolution II. The Mean Metal Abundance of the Universe
- Edmunds And Phillipps; M. G. Edmunds
We examine the metallicity distribution within and between galaxies and hence determine their present day mean abundance. Adding in components for inter-galactic gas we arrive at an estimate of the mean metal abundance of the universe. We find the pleasantly Copernican result that the overall mean abundance is close to solar. We then discuss the evolution with time of this quantity, using simplified, but general, models of galactic chemical evolution. The variation of the total metal content of the universe with epoch turns out to be constrained within fairly well defined limits for plausible variations in the global mean star...
Dimensions of Consistency in Source Versions and System Compositions (Extended Abstract)
- Dewayne E. Perry
Dewayne E. Perry Software and Systems Research Center AT&T Bell Laboratories Murray Hill, NJ 07974 1. Introduction Among the various issues that must be addressed in the building of software systems, there are two issues that fall within the province of version and configuration management: component derivation and component consistency --- that is, recording or determining the derivation of one component from another, and determining whether the components within a particular configuration are consistent with each other. Much of the past and current work in version and configuration management has addressed the problem of keeping track of how components are...
A Comparative Study of Approaches to Chance Discovery
- Helmut Prendinger; Mitsuru Ishizuka
: This paper gives an initial evaluation of approaches to chance discovery and management, a new research field invented by Yukio Ohsawa. Our aims in this preliminary report are very modest. First, we briefly describe research work done with the intent to detect chances (i.e., opportunities and risks) in various application areas such as the web, natural disasters, or histories of bankruptcy. Second, we raise some methodological questions about the feasibility of chance discovery as a research field. 1 Introduction Despite its infancy as a research field, chance discovery has already attracted considerable interest from researchers of various disciplines, including...
Automated Construction of Fuzzy Event Sets and Its Application to Active Databases
- Yücel Saygin; Özgür Ulusoy; Ozgur Ulusoy
Fuzzy sets and fuzzy logic research aims to bridge the gap between the crisp world of math and the real world. Fuzzy set theory was applied to many different areas, from control to databases. Sometimes the number of events in an event-driven system may become very high and unmanageable. Therefore, it is very useful to organize the events into fuzzy event sets also introducing the benefits of the fuzzy set theory. All the events that have occurred in a system can be stored in event histories which contain precious hidden information. In this paper, we propose a method for automated...
Path-Based Next Trace Prediction
- Quinn Jacobson; Quinn Jacobson; Eric Rotenberg; Eric Rotenberg; James E. Smith; James E. Smith
The trace cache has been proposed as a mechanism for providing increased fetch bandwidth by allowing the processor to fetch across multiple branches in a single cycle. But to date predicting multiple branches per cycle has meant paying a penalty in prediction accuracy. We propose a next trace predictor that treats the traces as basic units and explicitly predicts sequences of traces. The predictor collects histories of trace sequences (paths) and makes predictions based on these histories. The basic predictor is enhanced to a hybrid configuration that reduces performance losses due to cold starts and aliasing in the prediction table....
Prediction Outcome History-based Confidence Estimation for Load Value Prediction
- Martin Burtscher; Benjamin G. Zorn
Load instructions occasionally incur very long latencies that can significantly affect system performance. Load value prediction alleviates this problem by allowing the CPU to speculatively continue processing without having to wait for the slow memory access to complete. Current load value predictors can only correctly predict about forty to seventy percent of the fetched load values. To avoid the cycle-penalty for mispredictions in the remaining cases, confidence estimators are employed. They inhibit all predictions that are not likely to be correct. In this paper we present a novel confidence estimator that is based on prediction outcome histories. Profiles are used...
A Method for Calculating Transient Surface Temperatures and Surface Heating Rates for High-Speed Aircraft
- Robert Quinn Analytical; Robert D. Quinn; Leslie Gong
This report describes a method that can calculate transient aerodynamic heating and transient surface temperatures at supersonic and hypersonic speeds. This method can rapidly calculate temperature and heating rate time-histories for complete flight trajectories. Semi-empirical theories are used to calculate laminar and turbulent heat transfer coefficients and a procedure for estimating boundary-layer transition is included. Results from this method are compared with flight data from the X-15 research vehicle, YF-12 airplane, and the Space Shuttle Orbiter. These comparisons show that the calculated values are in good agreement with the measured flight data. NOMENCLATURE a speed of sound, ft/sec Btu British...
Inferences from DNA data: population histories, evolutionary processes, and forensic match probabilities.
- Ian J. Wilson; Michael E. Weale; David J. Balding
We develop a flexible class of...
Welfare Reform and Child Well-being
- Greg Duncan Lindsay; Greg J. Duncan; Greg J. Duncan; P. Lindsay Chase-lansdale; P. Lindsay Chase-lansdale
Plunging caseloads and soaring employment among single mothers lead many to judge welfare reform a stunning success. Lost in the caseload counts and political rhetoric is the subject of our chapter: welfare reform and children. We sort through conflicting theory and evidence regarding the impacts of welfare reform on children's well-being and development. A brief examination of recent trends in national indicators of potential problems shows that the sky has not fallen. Poverty rates are down, as are teen crime and fertility as well as substantiated cases of child maltreatment. However, the dearth of timely and consistent statelevel data on...
Automatic Comparison of Execution Histories in the Debugging of Distributed Applications
- Zhi Han
Trends in the development of computer hardware are making the use of distributed systems increasingly attractive. The collection of events representing interactions between processes and the construction of process-time diagrams can provide a useful visualization tool. In practical situations, however, these diagrams are too large for users find them comprehensible. The ability to automatically compare two execution diagrams and locate the differences between them can help to alleviate this problem. This thesis
Welfare Reform and Child Well-being
- Greg Duncan Lindsay; Greg J. Duncan; P. Lindsay Chase-lansdale
Plunging caseloads and soaring employment among single mothers lead many to judge welfare reform a stunning success. Lost in the caseload counts and political rhetoric is the subject of our chapter: welfare reform and children. We sort through conflicting theory and evidence regarding the impacts of welfare reform on childrens well-being and development. A brief examination of recent trends in national indicators of potential problems shows that the sky has not fallen. Poverty rates are down, as are teen crime and fertility as well as substantiated cases of child maltreatment. However, the dearth of timely and consistent statelevel data on...
The Astrophysical Journal, submitted Preprint typeset using L ATEX style emulateapj v. 10/09/06 THE STAR FORMATION HISTORIES OF RED-SEQUENCE GALAXIES, MASS-TO-LIGHT RATIOS AND THE FUNDAMENTAL PLANE
- Steven P. Allanson; Michael J. Hudson; Russell J. Smith; John R. Lucey
This paper addresses the challenge of understanding the typical star formation histories of red sequence galaxies, using linestrength indices and mass-to-light ratios as complementary constraints on their stellar age distribution. We first construct simple parametric models of the star formation history that bracket a range of scenarios, and fit these models to the linestrength indices of lowredshift cluster red-sequence galaxies. For giant galaxies, we confirm the downsizing trend, i.e. the stellar populations are younger, on average, for lower σ galaxies. We find, however, that this trend flattens or reverses at σ � 70kms −1. We then compare predicted stellar mass-to-light...
Virgo Early-Type Dwarfs in ALFALFA
- Jonathan I. Davies; Michael D. Disney; Rebecca A. Koopmann
Abstract. Early-type dwarf galaxies dominate cluster populations, but their formation and evolutionary histories are poorly understood. The ALFALFA (Arecibo Legacy Fast ALFA) survey has completed observations of the Virgo Cluster in the declination range of 6- 16 degrees. Less than 2 % of the early-type dwarf population is detected, a significantly lower fraction than reported in previous papers based on more limited samples. In contrast ∼30 % of the irregular/BCD dwarf population is detected. The detected early-type galaxies tend to be located in the outer regions of the cluster, with a concentration in the direction of the M Cloud. Many...
and tutored by
- De Ciencias; César Óscar; Seoánez Erkell; Profesor De Investigación; Prof Guillermo; Gómez Santos
Madrid, 2007iiTo my parents and grandparentsivResumen Los procesos de decoherencia y disipación en sistemas mesoscópicos han sido objeto en las últimas décadas de gran interés dado su papel clave en el estudio y utilización de fenómenos cuánticos a escalas cada vez mayores. Los espectaculares logros alcanzados en las técnicas de fabricación y medición han permitido el diseño de nanoestructuras móviles que hábilmente combinadas con otros protagonistas de la historia física reciente, tales como puntos cuánticos o gases electrónicos de baja dimensionalidad, otorgan la fascinante oportunidad de estudiar la interacción electrónfonón cuanto a cuanto, con un potencial tecnológico prometedor. En la...
Preprint typeset using L ATEX style emulateapj v. 10/09/06 EUROPIUM, SAMARIUM, AND NEODYMIUM ISOTOPIC FRACTIONS IN METAL-POOR STARS
- Ian U. Roederer; James E. Lawler; Christopher Sneden; John J. Cowan; Jennifer S. Sobeck; Catherine A
We have derived isotopic fractions of europium, samarium, and neodymium in two metal-poor giants with differing neutron-capture nucleosynthetic histories. These isotopic fractions were measured from new high resolution (R ∼ 120, 000), high signal-to-noise (S/N ∼ 160–1000) spectra obtained with the 2dCoudé spectrograph of McDonald Observatory’s 2.7m Smith telescope. Synthetic spectra were generated using recent high-precision laboratory measurements of hyperfine and isotopic subcomponents of several transitions of these elements and matched quantitatively to the observed spectra. We interpret our isotopic fractions by the nucleosynthesis predictions of the stellar model, which reproduces s-process nucleosynthesis from the physical conditions expected in low-mass,...