A class of algorithms for rational approximation of functions formally defined by power series

Corresponding sequence algorithms are defined and shown to exist for a wide range of corresponding continued fractions. Particular examples of these algorithms are given, including an algorithm for forming Pade approximants, and an error analysis is given in one case

Alcohol consumption is associated with increased all-cause mortality in Russian men and women: a cohort study based on the mortality of relatives

Objectives: To examine the relationships between frequency of alcohol consumption and of binge drinking and adult mortality in Russian men and women.Methods : Using modified indirect demographic techniques, a convenience cohort was constructed based on survey respondents? information about their close relatives. A random sample general population of the Russian Federation of 7172 respondents (response rate 61%) provided information on 10475 male and 3129 female relatives, including age, vital status and frequency of alcohol consumption and binge drinking. These relatives formed the cohort analysed in this report. The outcome measure was all-cause mortality after the age of 30 years.Findings: There was a strong linear relationship between frequency of drinking and of binge drinking and all-cause mortality in men; after controlling for smoking and calendar period of birth, the relative risk of death in daily drinkers compared to occasional drinkers was 1.52 (95% CI 1.33 ?1.75). Male binge drinkers had higher mortality than drinkers who did not binge, which persisted after adjustment for drinking frequency (adjusted RR 1.09 (1.00-1.19). In women, the increased mortality was confined to a small group of those who binged at least once a month (adjusted relative risk 2.68, 1.54-4.66). Conclusions: The results suggest a positive association between alcohol and mortality in Russia. There was no evidence for the protective effect of drinking seen in western populations. Alcohol appears to have contributed to the high long-term mortality rates in Russian men, but it is unlikely to be a major cause of female mortality. Objectives: To examine the relationships between frequency of alcohol consumption and of binge drinking and adult mortality in Russian men and women.Methods : Using modified indirect demographic techniques, a convenience cohort was constructed based on survey respondents? information about their close relatives. A random sample general population of the Russian Federation of 7172 respondents (response rate 61%) provided information on 10475 male and 3129 female relatives, including age, vital status and frequency of alcohol consumption and binge drinking. These relatives formed the cohort analysed in this report. The outcome measure was all-cause mortality after the age of 30 years.Findings: There was a strong linear relationship between frequency of drinking and of binge drinking and all-cause mortality in men; after controlling for smoking and calendar period of birth, the relative risk of death in daily drinkers compared to occasional drinkers was 1.52 (95% CI 1.33 ?1.75). Male binge drinkers had higher mortality than drinkers who did not binge, which persisted after adjustment for drinking frequency (adjusted RR 1.09 (1.00-1.19). In women, the increased mortality was confined to a small group of those who binged at least once a month (adjusted relative risk 2.68, 1.54-4.66). Conclusions: The results suggest a positive association between alcohol and mortality in Russia. There was no evidence for the protective effect of drinking seen in western populations. Alcohol appears to have contributed to the high long-term mortality rates in Russian men, but it is unlikely to be a major cause of female mortality

Pilot workload and fatigue: A critical survey of concepts and assessment techniques

The principal unresolved issues in conceptualizing and measuring pilot workload and fatigue are discussed. These issues are seen as limiting the development of more useful working concepts and techniques and their application to systems engineering and management activities. A conceptual analysis of pilot workload and fatigue, an overview and critique of approaches to the assessment of these phenomena, and a discussion of current trends in the management of unwanted workload and fatigue effects are presented. Refinements and innovations in assessment methods are recommended for enhancing the practical significance of workload and fatigue studies

Aircrew coordination and decisionmaking: Peer ratings of video tapes made during a full mission simulation

Six professionally active, retired captains rated the coordination and decisionmaking performances of sixteen aircrews while viewing videotapes of a simulated commercial air transport operation. The scenario featured a required diversion and a probable minimum fuel situation. Seven point Likert-type scales were used in rating variables on the basis of a model of crew coordination and decisionmaking. The variables were based on concepts of, for example, decision difficulty, efficiency, and outcome quality; and leader-subordin ate concepts such as person and task-oriented leader behavior, and competency motivation of subordinate crewmembers. Five-front-end variables of the model were in turn dependent variables for a hierarchical regression procedure. The variance in safety performance was explained 46%, by decision efficiency, command reversal, and decision quality. The variance of decision quality, an alternative substantive dependent variable to safety performance, was explained 60% by decision efficiency and the captain's quality of within-crew communications. The variance of decision efficiency, crew coordination, and command reversal were in turn explained 78%, 80%, and 60% by small numbers of preceding independent variables. A principle component, varimax factor analysis supported the model structure suggested by regression analyses

Remote sensing applied to land-use studies in Wyoming

Impending development of Wyoming's vast fuel resources requires a quick and efficient method of land use inventory and evaluation. Preliminary evaluations of ERTS-1 imagery have shown that physiographic and land use inventory maps can be compiled by using a combination of visual and automated interpretation techniques. Test studies in the Powder River Basin showed that ERTS image interpretations can provide much of the needed physiographic and land use information. Water impoundments as small as one acre were detected and water bodies larger than five acres could be mapped and their acreage estimated. Flood plains and irrigated lands were successfully mapped, and some individual crops were identified and mapped. Coniferous and deciduous trees were mapped separately using color additive analysis on the ERTS multispectral imagery. Gross soil distinctions were made with the ERTS imagery, and were found to be closely related to the bedrock geology. Several broad unstable areas were identified. These were related to specific geologic and slope conditions and generally extended through large regions. Some new oil fields and all large open-cut coal mines were mapped. The most difficult task accomplished was that of mapping urban areas. Work in the urban areas provides a striking example of snow enhancement and the detail available from a snow enhanced image

Teacher and student perceptions of the development of learner autonomy : a case study in the biological sciences

Biology teachers in a UK university expressed a majority view that student learning autonomy increases with progression through university. A minority suggested that pre-existing diversity in learning autonomy was more important and that individuals not cohorts differ in their learning autonomy. They suggested that personal experience prior to university and age were important and that mature students are more autonomous than 18-20 year olds. Our application of an autonomous learning scale (ALS) to four year-groups of biology students confirmed that the learning autonomy of students increases through their time at university but not that mature students are necessarily more autonomous than their younger peers. It was evident however that year of study explained relatively little

PassGAN: A Deep Learning Approach for Password Guessing

State-of-the-art password guessing tools, such as HashCat and John the Ripper, enable users to check billions of passwords per second against password hashes. In addition to performing straightforward dictionary attacks, these tools can expand password dictionaries using password generation rules, such as concatenation of words (e.g., "password123456") and leet speak (e.g., "password" becomes "p4s5w0rd"). Although these rules work well in practice, expanding them to model further passwords is a laborious task that requires specialized expertise. To address this issue, in this paper we introduce PassGAN, a novel approach that replaces human-generated password rules with theory-grounded machine learning algorithms. Instead of relying on manual password analysis, PassGAN uses a Generative Adversarial Network (GAN) to autonomously learn the distribution of real passwords from actual password leaks, and to generate high-quality password guesses. Our experiments show that this approach is very promising. When we evaluated PassGAN on two large password datasets, we were able to surpass rule-based and state-of-the-art machine learning password guessing tools. However, in contrast with the other tools, PassGAN achieved this result without any a-priori knowledge on passwords or common password structures. Additionally, when we combined the output of PassGAN with the output of HashCat, we were able to match 51%-73% more passwords than with HashCat alone. This is remarkable, because it shows that PassGAN can autonomously extract a considerable number of password properties that current state-of-the art rules do not encode.Comment: This is an extended version of the paper which appeared in NeurIPS 2018 Workshop on Security in Machine Learning (SecML'18), see https://github.com/secml2018/secml2018.github.io/raw/master/PASSGAN_SECML2018.pd

A semantic web approach for built heritage representation

In a built heritage process, meant as a structured system of activities aimed at the investigation, preservation, and management of architectural heritage, any task accomplished by the several actors involved in it is deeply influenced by the way the knowledge is represented and shared. In the current heritage practice, knowledge representation and management have shown several limitations due to the difficulty of dealing with large amount of extremely heterogeneous data. On this basis, this research aims at extending semantic web approaches and technologies to architectural heritage knowledge management in order to provide an integrated and multidisciplinary representation of the artifact and of the knowledge necessary to support any decision or any intervention and management activity. To this purpose, an ontology-based system, representing the knowledge related to the artifact and its contexts, has been developed through the formalization of domain-specific entities and relationships between them

Eclipsing high-mass binaries I. Light curves and system parameters for CPD-518946, PISMIS24-1 and HD319702

We present first results of a comprehensive photometric O-star survey performed with a robotic twin refractor at the Universit\"atssternwarte Bochum located near Cerro Armazones in Chile. For three high-mass stars, namely Pismis24-1, CPD-518946 and HD319702, we determined the period through the Lafler-Kinman algorithm and model the light curves within the framework of the Roche geometry. For Pismis24-1, a previously known eclipsing binary, we provide first light curves and determined a photometric period of 2.36 days together with an orbital inclination of 61.8 degrees. The best-fitting model solution to the light curves suggest a detached configuration. With a primary temperature of T1 = 42520K we obtain the temperature of the secondary component as T2 = 41500K. CPD-518946 is another known eclipsing binary for which we present a revised photometric period of 1.96 days with an orbital inclination of 58.4 degrees. The system has likely a semi-detached configuration and a mass ratio q = M1/M2 = 2.8. If we adopt a primary temperature of T1 = 34550K we obtain T2 = 21500K for the secondary component. HD319702 is a newly discovered eclipsing binary member of the young open cluster NGC6334. The system shows well-defined eclipses favouring a detached configuration with a period of 2.0 days and an orbital inclination of 67.5 degrees. Combining our photometric result with the primary spectral type O8 III(f) (T1 = 34000K) we derive a temperature of T2 = 25200K for the secondary component.Comment: 7 pages, 4 figures, accepted for publication in Astronomy and Astrophysic