DIRECT RESONANCE OF TURBULENT BOUNDARY LAVER OVER COMPLIANT WALLS

１．　ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅｍａｉｎｇｏａｌｏｆｔｈｉｓｐａｐｅｒｉｓｔｏｅｘｐｌｏｒｅｔｈｅｐｏｓｓｉｂｉｌｉｔｙｔｏｌｅａｒｎｍｏｒｅａｂｏｕｔｔｈｅｍｅｃｈａｎｉｓｍｏｆｔｕｒｂｕｌｅｎｔｂｏｕｎｄａｒｙｌａｙｅｒｆｌｏｗｉｎｔｅｒａｃｔｉｏｎｓａｎｄｉｔｓｅｆｆｅｃｔｓｏｎｃｏｍｐｌｉａｎｔｗａｌｌｐｅｒｆｏｒｍａｎｃｅ．Ｔｈｅｒｅａｒｅｃｅｒｔａｉｎｐｒｅｒｅｑｕｉｓｉｔｅｃｏｎｄｉｔｉｏｎｓｔｏｆｕｒｔｈｅｒｔｈｅｓｔｕｄｙｏｎｔｈｅｍｅｃｈａｎｉｓｍ，ｉ．ｅ．ｔｈｅｃｏ…     

Futures assessment by field anomaly relaxation : A review and appraisal

Futures research includes the problem of generating reasonably exhaustive and plausible scenarios for a given topic, a problem for which there are no truly satisfactory solutions. This article reviews and evaluates a method, field anomaly relaxation, first put forward some 20 years ago. The evaluation is in the context of an illustrative study of political developments in Europe. The research reconstructs and further develops the method and concludes that it has something to offer for scenario generation. Its weaknesses are identified and suggestions for further research are made.     

Programme Evaluation with Unobserved Heterogeneity and Selective Implementation: The Mexican PROGRESA Impact on Child Nutrition

This paper considers the impact of Programa de Educación, Salud y Alimentación ( PROGRESA ), a large Mexican rural anti-poverty programme that had an evaluation sample in which overall treatment was randomly assigned to some communities but not others, on child nutrition. When we examine the impact of PROGRESA based on the presumption of randomized allocations, we find that PROGRESA had no or even a negative impact on child nutrition. However, not all children designated to receive nutritional supplements actually did so. Our preferred estimates – child fixed-effects estimates that control for unobserved heterogeneity that is correlated with access to the supplement – indicate a significantly positive and fairly substantial programme effect of the nutritional supplements on children 12–36 months. They imply an increase of about a sixth in mean growth per year for these children and a lower probability of stunting. Effects are somewhat larger for children from poorer communities but whose mothers are functionally literate. The long-term consequences of these improvements are non-trivial; its impact working through adult height alone could result in a 2.9% increase in lifetime earnings.     

The Economics and Financing of Hospitals in Australia

The Australian hospital industry is described and it is noted that the term ‘hospital’ is applied to a wide range of institutions. The main problems and issues associated with hospitals are discussed, including the lack of adequate methods of measuring their ‘products’ and of allocating funds to them. The role of the medical staff in influencing the ‘demand’ for hospital beds and in resource allocation is emphasised as a major influence on hospital behaviour. In a study of the determinants of the costs of Victorian public hospitals it was found that the complexity of the case-mix as measured by diagnosis related groups (DRGs) was a major determinant of teaching hospital costs but not of those of other large hospitals. DRG-based funding and costing of hospitals is recommended as a strategy for achieving increased efficiency.     

Reform of European Merger Policy

The paper highlights the main drivers for merger policy reform in the European Union, including the consequences of the recent appeal court reverses. It discusses some of the substantive and procedural issues that the reform package should address, and outlines the reforms in progress. The author concludes that much of the reform package will be beneficial, but some important opportunities have been missed in this inevitably patchwork process.     

Disentangling the Dividend Information in Splits: A Decomposition Using Conditional Event-Study Methods

While folklore in finance holds that split valuation effectsare due to dividend increases associated with splits, littleis known about magnitudes of dividend and nondividend componentsof split announcement effects. We find that splits and dividendsare indeed informational substitutes, a notion we characterizemore precisely, but a significant portion of split valuationeffects, 46% according to our estimates, cannot be attributedto dividend information in splits. Our techniques extend theliterature on conditional event-study methods and we illustratetheir practical value in testing hypotheses and analyzing datanot amenable to analysis by standard procedures.     

Economic Growth and Productivity Gains from Capital Inflow: A Rejoinder

Journal of Quantitative Economics -     

Retention of Escherichia coli in municipal sewage by means of planted soil filters in two-stage pilot plant systems.

Different types of constructed wetlands in a pilot-plant system were fed with identical municipal waste water to compare the sanitisation process in two-stage systems. With combinations of a vertical and a horizontal flow filter an E. coli reduction of 5 log10 with an E. coli influent concentration of 10(7) MPN/100 ml was achieved. Using different filter materials in each stage the total performance of the two-stage system was independent from the sequence of these materials. However, using coarser filter material in the first stage makes the filter less prone to clogging and is thus the preferential option with regard to operational reliability.     

Option-Implied Risk Aversion Estimates

Using a utility function to adjust the risk‐neutral PDF embedded in cross sections of options, we obtain measures of the risk aversion implied in option prices. Using FTSE 100 and S&P 500 options, and both power and exponential‐utility functions, we estimate the representative agent's relative risk aversion (RRA) at different horizons. The estimated coefficients of RRA are all reasonable. The RRA estimates are remarkably consistent across utility functions and across markets for given horizons. The degree of RRA declines broadly with the forecast horizon and is lower during periods of high market volatility.