290 research outputs found
Measures of Predictive Success for Rating Functions
Aim of our paper is to develop an adequate measure of predictive success and accuracy of rating functions. At first, we show that the common measures of rating accuracy, i.e. area under curve and accuracy ratio, respectively, lack of informative value of single rating classes. Selten (1991) builds up an axiomatic framework for measures of predictive success. Therefore, we introduce a measure for rating functions that fulfills the axioms proposed by Selten (1991). Furthermore, an empirical investigation analyzes predictive power and accuracy of Standard & Poor's and Moody's ratings, and compares the rankings according to area under curve and our measure.Accuracy Measure, Rating Functions, Predictive Success, Discriminative Power
Dividend Yield and Stability versus Performance at the German Stock Market
It is often examined in the literature whether the dividend yields of stocks correlate with their total returns. This paper analyzes the effect of dividend yield on return as well as on risk and on performance of stocks and stock portfolios. Not only the influence of dividend yield but also of dividend stability is subject of our analysis. Furthermore, tax aspects are considered. Our data set comprises daily adjusted stock prices and dividend payment data from the German capital market over the period 2000 to 2006. We use stocks from the HDAX, which include blue chips (DAX), stocks of medium-sized companies (MDAX), and stocks of technology firms (TecDAX). Our findings suggest that the performance generally improves with an increasing dividend yield. However, this result is rather based on risk reduction than on a higher return where risk reduction diminishes by increasing the degree of diversification.dividend yield, dividend stability, diversification, performance
Measures of Predictive Success for Rating Functions
Aim of our paper is to develop an adequate measure of predictive success and accuracy of rating functions. At first, we show that the common measures of rating accuracy, i.e. area under curve and accuracy ratio, respectively, lack of informative value of single rating classes. Selten (1991) builds up an axiomatic framework for measures of predictive success. Therefore, we introduce a measure for rating functions that fulfills the axioms proposed by Selten (1991). Furthermore, an empirical investigation analyzes predictive power and accuracy of Standard & Poor\u27s and Moody\u27s ratings, and compares the rankings according to area under curve and our measure.Aim of our paper is to develop an adequate measure of predictive success and accuracy of rating functions. At first, we show that the common measures of rating accuracy, i.e. area under curve and accuracy ratio, respectively, lack of informative value of single rating classes. Selten (1991) builds up an axiomatic framework for measures of predictive success. Therefore, we introduce a measure for rating functions that fulfills the axioms proposed by Selten (1991). Furthermore, an empirical investigation analyzes predictive power and accuracy of Standard & Poor\u27s and Moody\u27s ratings, and compares the rankings according to area under curve and our measure
Dividend Yield and Stability versus Performance at the German Stock Market
It is often examined in the literature whether the dividend yields of stocks correlate with their total returns. This paper analyzes the effect of dividend yield on return as well as on risk and on performance of stocks and stock portfolios. Not only the influence of dividend yield but also of dividend stability is subject of our analysis. Furthermore, tax aspects are considered. Our data set comprises daily adjusted stock prices and dividend payment data from the German capital market over the period 2000 to 2006. We use stocks from the HDAX, which include blue chips (DAX), stocks of medium-sized companies (MDAX), and stocks of technology firms (TecDAX). Our findings suggest that the performance generally improves with an increasing dividend yield. However, this result is rather based on risk reduction than on a higher return where risk reduction diminishes by increasing the degree of diversification
Operational issues involving use of supplementary cooling towers to meet stream temperature standards with application to the Browns Ferry Nuclear Plant
A mixed mode cooling system is one which operates in either the open,
closed, or helper (once-through but with the use of the cooling towers) modes.
Such systems may be particularly economical where the need for supplementary
cooling to meet environmental constraints on induced water temperature
changes is seasonal or dependent upon other transient factors such as stream-
flow. The issues involved in the use of mixed mode systems include the
design of the open cycle and closed cycle portions of the cooling system,
the specification of the environmental standard to be met, and the monitoring
system and associated decision rules used to determine when mode changes
are necessary. These issues have been examined in the context of a
case study of TVA's Browns Ferry Nuclear Plant which utilizes the large
quantity of site specific data reflecting conditions both with and without
plant operation. The most important findings of this study are: (1) The
natural temperature differences in the Tennessee River are of the same order
of magnitude (50F) as the maximum allowed induced temperature increase.
(2) Predictive estimates based on local hydrological and meteorological
data are capable of accounting for 40% of the observed natural variability.
(3) Available algorithms for plant induced temperature increases provide
estimates within 1F of observed values except during periods of strong
stratification. (4) A mixed mode system experiences only 10% of the
capacity losses experienced by a totally closed system, (5) The capacity
loss is relatively more sensitive to the environmental standard than to
changes in cooling system design. (6) About one third of the capacity
loss incurred using the mixed mode system is the result of natural
temperature variations. This unnecessary loss may be halved by the use
of predictive estimates for natural temperature differences
Introduction DASTS 2022 special issue
This STS Encounters special issue is a collection of articles that has been developed from conference papers presented at the bi-yearly Danish Association for Science and Technology studies (DASTS) conference in 2022. The conference was held at the Department of Digital Design and Information studies, Aarhus University and hosted by the STS center at Aarhus University on June 2-3. 2022. The theme of the conference was: 'Living with Ruptures: Repair, Maintenance, and (Re)Construction'. 
Liposome Encapsulation Of A Photochemical No Precursor For Controlled Nitric Oxide Release And Simultaneous Fluorescence Imaging
Described are photochemical studies of the nitric oxide precursors, trans-Cr(L)(ONO)(2)(+) (L = cyclam = 1,4,8,11-tetraazacyclotetradecane, CrONO, or L = mac = 5,7-dimethyl-6-anthracenylcyclam, mac-CrONO) encapsulated in phosphatidylcholine liposomes. The liposomes provide a means to maintain a localized high concentration of NO releasing complexes and are easily modified for in vivo targeting through self-assembly. Steady, controlled release of NO is seen after photolysis of the liposome-encapsulated CrONO as compared to the burst of NO release seen by the unencapsulated complex in oxygenated solutions. The quantum yields for photochemical NO release from liposome-encapsulated CrONO and mac-CrONO were determined in both oxygenated and anoxic solutions. The quantum yield for NO release in oxygenated solution for encapsulated CrONO was more than 5 times larger than that of unencapsulated CrONO, thus the net NO released after photolysis in oxygenated solutions is enhanced by encapsulation of CrONO in liposomes. Encapsulated mac-CrONO shows NO release after photolysis with low-intensity blue light. Furthermore, the fluorescence of mac-CrONO can be detected through the liposomes, thus allowing for development of theranostic NO delivery vessels where tracking and imaging can occur simultaneously with therapeutic NO release. This work provides insight into the development of multifunctional liposome constructs for disease theranostics
Eastern Boundary Circulation and Hydrography Off Angola: Building Angolan Oceanographic Capacities: Building Angolan Oceanographic Capacities
The eastern boundary region off Angola encompasses a highly productive ecosystem important for the food security of the coastal population. The fish-stock distribution, however, undergoes large variability on intraseasonal, interannual, and longer time scales. These fluctuations are partly associated with large-scale warm anomalies that are often forced remotely from the equatorial Atlantic and propagate southward, reaching the Benguela upwelling off Namibia. Such warm events, named Benguela Niños, occurred in 1995 and in 2011. Here we present results from an underexplored extensive in situ dataset that was analyzed in the framework of a capacity-strengthening effort. The dataset was acquired within the Nansen Programme executed by the Food and Agriculture Organization of the United Nations and funded by the Norwegian government. It consists of hydrographic and velocity data from the Angolan continental margin acquired biannually during the main downwelling and upwelling seasons over more than 20 years. The mean seasonal changes of the Angola Current from 6° to 17°S are presented. During austral summer the southward Angola Current is concentrated in the upper 150 m. It strengthens from north to south, reaching a velocity maximum just north of the Angola Benguela Front. During austral winter the Angola Current is weaker, but deeper reaching. While the southward strengthening of the Angola Current can be related to the wind forcing, its seasonal variability is most likely explained by coastally trapped waves. On interannual time scales, the hydrographic data reveal remarkable variability in subsurface upper-ocean heat content. In particular, the 2011 Benguela Niño was preceded by a strong subsurface warming of about 2 years’ duration
Porcine Reproductive and Respiratory Syndrome Virus: Origin Hypothesis
Porcine reproductive and respiratory syndrome is a serious swine disease that appeared suddenly in the midwestern United States and central Europe approximately 14 years ago; the disease has now spread worldwide. In North America and Europe, the syndrome is caused by two genotypes of porcine reproductive and respiratory syndrome virus (PRRSV), an arterivirus whose genomes diverge by approximately 40%. My hypothesis, which explains the origin and evolution of the two distinct PRRSV genotypes, is that a mutant of a closely related arterivirus of mice (lactate dehydrogenase-elevating virus) infected wild boars in central Europe. These wild boars functioned as intermediate hosts and spread the virus to North Carolina in imported, infected European wild boars in 1912; the virus then evolved independently on the two continents in the prevalent wild hog populations for approximately 70 years until independently entering the domestic pig population
Modeling Human Cancer-induced Cachexia
Talbert et al. developed an inducible mouse model of cachexia caused by pancreatic cancer. This model exhibits features of the human condition, including the progressive depletion of muscle and adipose tissue associated with tumor progression
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