A hybrid ant algorithm for scheduling independent jobs in heterogeneous computing environments

The efficient scheduling of independent computational jobs in a heterogeneous computing (HC) environment is an important problem in domains such as grid computing. Finding optimal schedules for such an environment is (in general) an NP-hard problem, and so heuristic approaches must be used. In this paper we describe an ant colony optimisation (ACO) algorithm that, when combined with local and tabu search, can find shorter schedules on benchmark problems than other techniques found in the literature

A fast, effective local search for scheduling independent jobs in heterogeneous computing environments

The efficient scheduling of independent computational jobs in a heterogeneous computing (HC) environment is an important problem in domains such as grid computing. Finding optimal schedules for such an environment is (in general) an NP-hard problem, and so heuristic approaches must be used. Work with other NP-hard problems has shown that solutions found by heuristic algorithms can often be improved by applying local search procedures to the solution found. This paper describes a simple but effective local search procedure for scheduling independent jobs in HC environments which, when combined with fast construction heuristics, can find shorter schedules on benchmark problems than other solution techniques found in the literature, and in significantly less time

A Photographic Study of Freezing of Water Droplets Falling Freely in Air

A photographic technique for investigating water droplets of diameter less than 200 microns falling freely in air at temperatures between 0 C and -50 C has been devised and used to determine: (i) The shape of frozen droplets (2) The occurrence of collisions of partly frozen or of frozen and liquid droplets (3) The statistics on the freezing temperatures of individual free-falling droplets A considerable number of droplets were found to have a nonspherical shape after freezing because of various protuberances and frost growth, and droplet aggregates formed by collision. The observed frequency of collision of partly frozen droplets showed good order of magnitude agreement with the frequency computed from theoretical collection efficiencies. The freezing temperature statistics indicated a general similarity of the data to those obtained for droplets frozen on a metallic surface in previous experiments

Finance and growth : Schumpeter might be right

Joseph Schumpeter argued in 1911 that the services provided by financial intermediaries - mobilizing savings, evaluating projects, managing risk, monitoring managers, and facilitating transactions -stimulate technological innovation and economic development. The authors present evidence that supports this view. Examining a cross-section of about 80 countries for the period 1960-89, they find that various measures of financial development are strongly associated with both current and later rates of economic growth. Each measure has shortcomings but all tell the same story: finance matters. They present three main findings, which are robust to many specification tests: The average level of financial development for 1960-89 is very strongly associated with growth for the period. Financial development precedes growth. For example, financial depth in 1960 (the ratio of broad money to GDP) is positively and significantly related to real per capita GDP growth over the next 30 years even after controlling for a variety of country-specific characteristics and policy indicators. Financial development is positively associated with both investment rate and the efficiency with which economies use capital. Much work remains to be done, but the data are consistent with Schumpeter's view that the services provided by financial intermediaries stimulate long-run growth.Achieving Shared Growth,Governance Indicators,Economic Theory&Research,Inequality,Economic Growth

Financial indicators and growth in a cross section of countries

The authors use existing measures of the financial system - and construct many new measures - to document the relationship between the financial system and long-run growth in a cross-section of countries between 1960 and 1989. They consider various measures of the size of the financial system, the importance of different financial institutions, the financial system's allocation of credit, the financial system's efficiency, and the degree of financial repression. They use graphs, correlations, and regressions to gauge the robustness of the partial correlation between growth and the financial indicators. They also examine two channels through which financial indicators may be linked to growth: the share of GDP allocated to investment; and the efficiency with which resources are used. They find that many of the financial system indicators are significantly correlated with growth through both investment and efficiency. Moreover, many of these partial correlations remain strong after controlling for initial conditions, dummy variables for Africa and Latin America, and measures of monetary, fiscal, and trade performance. Their analysis suggests that it is empirically important to identify which financial intermediaries aredoing the intermediation and to whom the financial system is allocating credit rather than simply using proxies for the overall size of the financial system, as has been common in past studies.Economic Theory&Research,Macroeconomic Management,Financial Economics,Achieving Shared Growth,Governance Indicators

Capital fundamentalism, economic development, and economic growth

Few economic ideas are as intuitive as the notion that increasing investment is the best way to raise future output. This idea was the basis for the theory"capital fundamentalism."Under this view, differences in national stocks of capital were the primary determinants of differences in levels of national product. Capital fundamentalists viewed capital accumulation as central to increasing the rate of economic growth. Evidence to support this view was based mostly on case studies of less developed countries. Neoclassical growth theory and growth accounting research indicated that differences in patterns of investment and capital formation were not the main factors that led nations to be rich or poor, fast-growing or slow. Technology, rather than capital accumulation, appeared to drive improvements in living standards in the long run. Evidence to support this view was based mostly on data from advanced countries. Recent research on growth and development has lent support to two conclusions that capital fundamentalists would find attractive: that differences in national patterns of physical capital accumulation can explain many differences in levels of national product, and that increases in national investment rates can produce major increases in rates of economic growth. The authors find that although the capital-output ratio varies positively with the level of per capita income, there is little support for the view that capital fundamentalism should guide the agenda for research and policy advice. Extending standard growth accounting procedures to a broad sample of 105 countries, they find: 1) differences in capital-per-person explain few of the differences in output-per-person across countries; 2) growth in capital stocks account for little of output growth across countries; and 3) the ratio of investment to Gross Domestic Product is strongly associated with economic growth - but there is more reason to believe that economic growth causes investment and savings than investment and savings cause economic growth.Economic Growth,Economic Theory&Research,Banks&Banking Reform,International Terrorism&Counterterrorism,Achieving Shared Growth

Palaeopathology and horse domestication: the case of some Iron Age horses horn the Altai Mountains, Siberia

We discuss the use of palaeopathological indicators in horse skeletons as potential sources I of evidence about the use of horses for riding and traction. We suggest that this type of information can provide an important and perhaps more reliable complement to other indicators of domestication such as morphological changes, kill-off patterns and bit wear, which suffer from various ambiguities of interpretation. We emphasise the importance of studying the skeletons of modern control samples of horses of known life histories as a constraint on the interpretation of palaeopathological evidence and demonstrate the viability of the technique through a comparison of free-living Exmoor ponies with Iron Age Scythian horse remains from Siberia. We demonstrate that stresses caused by riding produce characteristic lesions on the vertebrae which can be distinguished from age-related damage in free-living animals, and in addition that these stresses could have been moderated by changes of saddle design in the Medieval period. These results also throw new light on customs associated with horse burial