Exact properties of Efron's biased coin randomization procedure

Efron [Biometrika 58 (1971) 403--417] developed a restricted randomization procedure to promote balance between two treatment groups in a sequential clinical trial. He called this the biased coin design. He also introduced the concept of accidental bias, and investigated properties of the procedure with respect to both accidental and selection bias, balance, and randomization-based inference using the steady-state properties of the induced Markov chain. In this paper we revisit this procedure, and derive closed-form expressions for the exact properties of the measures derived asymptotically in Efron's paper. In particular, we derive the exact distribution of the treatment imbalance and the variance-covariance matrix of the treatment assignments. These results have application in the design and analysis of clinical trials, by providing exact formulas to determine the role of the coin's bias probability in the context of selection and accidental bias, balancing properties and randomization-based inference.Comment: Published in at http://dx.doi.org/10.1214/09-AOS758 the Annals of Statistics (http://www.imstat.org/aos/) by the Institute of Mathematical Statistics (http://www.imstat.org

Methodological Approaches to Management Systems Examination in Terms of Financial Crisis

The article is concerned with existing approaches to management systems examination in terms of financial crisis, brings in general approaches to companies’ management systems analysis, considers different decision making methods in terms of companies’ management system

Neki pokazatelji faznog prijelaza tekućina-plin u razbijanju jezgri 197Au elektronima

The energy spectra and fragment yields (5&lt;ZF&lt;10) obtained in 1.5 - 4.5 GeV e + 197Au inclusive reactions are analysed. Based on the observed correlation between a decrease in the fragment yields and an increase in the fragment Coulomb energy with the fragment charge, temperatures of the fragmenting system are derived. It is shown that the fragment yields exhibit the feature of thermal scaling in accordance with the Fisher\u27s droplet model. By using this model, values for the zero temperature surface energy coefficient, c0=11.8±0.8 MeV, the critical exponent, , σ = 0.56±0.03, as well as estimation of the critical temperature, Tc ≈ 18 MeV are obtained. The obtained results argue in favour of nuclear liquid-gas phase transition in these electron-induced reactions.Analiziramo energijske spektre i prinose izbačenih jezgri (5 < ZF < 10) u inkluzivnim reakcijama 1.5 – 4.5 GeV e + 197Au. Na osnovi opaženih korelacija smanjenja prinosa izbačenih jezgri i povećanja Coulombove energije s nabojem izbačenih jezgri izvodimo temperature udarenog sustava. Opažamo da prinosi izbačenih jezgri pokazuju toplinsko sumjeravanje u skladu s Fisherovim modelom kapljice. Primjenom tog modela izveli smo koeficijent površinske energije na temperaturnoj nuli, c0 = 11.8 ± 0.8 MeV, i kritični eksponent, σ = 0.56 ± 0.03, te ocijenili kritičnu temperaturu, Tc ≈ 18 MeV. Postignuti rezultati ukazuju na nuklearni fazni prijelaz tekućina-plin u tim reakcijama izazvanim elektronim

Several specific and nonspecific responses of the human and animal body to ship noise

The effect of noise on cargo boats on a long voyage differs considerably from the effect of noise in factories and in service industries. The peculiarities of the effect of round-the-clock noises at sea at 55 to 85 decibels, typical for cargo boats, were studied in white rats in the laboratory and aboard ship (each of the experiments lasted three months) and in young naval cadets and experienced seamen on voyages lasting one, two, and three months. The findings helped to derive health standards for maximum admissible noise level at sea

Problems and ways to overcome unemployment in Sochi

The article discloses social aspects of unemployment and ways to overcome it in Sochi Resort

Problems of Russian enterprises switch to modern quality management

The article determines the problems of enterprises switch to quality management system in the modern context, characterizes Total Quality Management

Eating air pollution using building's façade technology

The research is concerned with pollution in general and air pollution in particular. Through description and analysis, the research tackles the most prominent methods and means used in order to reduce air pollution using modern technologies. It also tackles the extent of the impact of the built environment on the natural environment. Thereby, the research seeks to reduce this effect through the architectural designer’s utilization of technology systems. Thus, the general research problem is formed; showing a lack of knowledge on how to deal with the pollution problems resulting from vehicle exhaust. Further, the research tackles the studies related to the special research problem, which is the lack of knowledge of modern techniques such as (biological filters) used in the buildings, its importance in dealing with air pollution resulting from vehicle exhaust, and its impact on the local environment. The aim of the research is to study and describe architectural buildings that use such technologies and demonstrate their importance in improving local environment. This is made by forming a methodology that includes two parts; the first is represented by air pollution, its sources and cause and the second is represented by studying the technologies, indicating their types and differences and how the architectural designer used it in buildings to reduce air pollution caused by vehicle exhaust. The research reached many conclusions and recommendations

Purpose and application peculiarities of management accounting in insurance companies

© 2015, MCSER-Mediterranean Center of Social and Educational Research. Organization of a management accounting in insurance companies allows to perform operational and strategic management of insurance business based on elaboration of alternative approaches in ultimate goals achievement. Management accounting is directed at satisfaction of information needs of management in all insurance business areas, including actuarial and investment activity. Centralization of the management accounting system along with the development of single information standards at the level of a parent company leads to significant reduction of the business operations of subsidiaries in favor of sales and client service. Management accounting system of the insurance business may serve as a source of information in terms of financial risks, sales and value management only provided it is developed on multi-criterion principle and is based on modern information technologies