8,710 research outputs found
Precise Modelling of Compensating Business Transactions and its Application to BPEL
We describe the StAC language which can be used to specify the orchestration of activities in long running business transactions. Long running business transactions use compensation to cope with exceptions. StAC supports sequential and parallel behaviour as well as exception and compensation handling. We also show how the B notation may be combined with StAC to specify the data aspects of transactions. The combination of StAC and B provides a rich formal notation which allows for succinct and precise specification of business transactions. BPEL is an industry standard language for specifying business transactions and includes compensation constructs. We show how a substantial subset of BPEL can be mapped to StAC thus demonstrating the expressiveness of StAC and providing a formal semantics for BPEL
Endogenous Health Care, Life Expectancy, and Economic Development
We study the endogenous relationship between health care, life expectancy and output in a modified neoclassical growth model. While health care competes resources away from goods production, it prolongs life expectancy which in turn leads to higher capital accumulation. We show that savings and health care are complements in equilibrium, with both rising with economic development. Our model is therefore consistent with several stylized facts, namely, (i) countries spend more on health care as they prosper, (ii) individuals in rich countries tend to live longer, and (iii) population aging is more pronounced in rich countries. Moreover, through simulation, health care and health production technology are found to be growth and welfare enhancing.life expectancy, health care, economic growth, population aging
Complex Network Approach to the Statistical Features of the Sunspot Series
Complex network approaches have been recently developed as an alternative
framework to study the statistical features of time-series data. We perform a
visibility-graph analysis on both the daily and monthly sunspot series. Based
on the data, we propose two ways to construct the network: one is from the
original observable measurements and the other is from a
negative-inverse-transformed series. The degree distribution of the derived
networks for the strong maxima has clear non-Gaussian properties, while the
degree distribution for minima is bimodal. The long-term variation of the
cycles is reflected by hubs in the network which span relatively large time
intervals. Based on standard network structural measures, we propose to
characterize the long-term correlations by waiting times between two subsequent
events. The persistence range of the solar cycles has been identified over
15\,--\,1000 days by a power-law regime with scaling exponent
of the occurrence time of the two subsequent and successive strong minima. In
contrast, a persistent trend is not present in the maximal numbers, although
maxima do have significant deviations from an exponential form. Our results
suggest some new insights for evaluating existing models. The power-law regime
suggested by the waiting times does indicate that there are some level of
predictable patterns in the minima.Comment: 18 pages, 11 figures. Solar Physics, 201
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