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51.
Continuous simulation is performed using the US Environmental Protection Agency (USEPA) Storm Water Management Model (SWMM) to evaluate regional differences around the United States in hydrologic and water quality performance of wet-weather controls. Controls are characterised as being limited by peak inflow rate (i.e. any device with little or no storage, such as screens, filters and some proprietary devices) or by storage capacity (e.g., ponds, tanks). For flow-limited devices, results are presented in the form of percentage of annual runoff volume captured (passing through the device) for a given inflow capacity. For storage-limited devices, results are presented in two forms: percentage of annual runoff volume captured as a function of unit basin size and drawdown (drain) time, and as a percentage of total suspended solids captured, for the same two variables. Regional differences are apparent, driven mainly by variations in rainfall patterns around the country. 相似文献
52.
53.
O Bernard B Chachuat A Hélias B Le Dantec B Sialve J-P Steyer L Lardon P Neveu S Lambert J Gallop M Dixon P Ratini A Quintabà S Frattesi J M Lema E Roca G Ruiz J Rodriguez A Franco P Vanrolleghem U Zaher D J W De Pauw K De Neve K Lievens D Dochaine O Schoefs H Fibrianto R Farina V Alcaraz Gonzalez V Gonzalez Alvarez P Lemaire J A Martinez F Esandi O Duclaud J F Lavigne 《Water science and technology》2005,52(1-2):457-464
The TELEMAC project brings new methodologies from the Information and Science Technologies field to the world of water treatment. TELEMAC offers an advanced remote management system which adapts to most of the anaerobic wastewater treatment plants that do not benefit from a local expert in wastewater treatment. The TELEMAC system takes advantage of new sensors to better monitor the process dynamics and to run automatic controllers that stabilise the treatment plant, meet the depollution requirements and provide a biogas quality suitable for cogeneration. If the automatic system detects a failure which cannot be solved automatically or locally by a technician, then an expert from the TELEMAC Control Centre is contacted via the internet and manages the problem. 相似文献
54.
If actively managed mutual funds suffer from diminishing returns to scale, funds should alter investment behavior as assets under management increase. Although asset growth has little effect on the behavior of the typical fund, we find that large funds and small‐cap funds diversify their portfolios in response to growth. Greater diversification, especially for small‐cap funds, is associated with better performance. Fund family growth is related to the introduction of new funds that hold different stocks from their existing siblings. Funds with many siblings diversify less rapidly as they grow, suggesting that the fund family may influence a fund's portfolio strategy. 相似文献
55.
Telework as an integration of Information and Telecommunication Technologies with Human Resources management, means a new job organisation paradigm for companies working in the New Economy. However there are very few empirical studies that have analysed the perception differences of telework benefits and barriers in industrial and service companies. This paper contributes with empirical data to the relationship between the use of telework techniques and the implementation of this new work organisation with the company's operations strategy. The paper uses data from Spanish companies to test the relationship between innovation, employee training, and other production strategy performance parameters with the feasibility of telework adoption. 相似文献
56.
There are two variance components embedded in the returns constructed using high frequency asset prices: the time-varying variance of the unobservable efficient returns that would prevail in a frictionless economy and the variance of the equally unobservable microstructure noise. Using sample moments of high frequency return data recorded at different frequencies, we provide a simple and robust technique to identify both variance components. 相似文献
57.
Models that assume only consumer tastes determine the characteristics of supply are restrictive; producers can gain utility from aspects of production and pay for deviating from demand by accepting lower financial returns. We model and measure motivations of California winery owners, and analyze their effects on quality and price. We find utility–maximizers are more likely to produce high quality and set higher quality–adjusted prices. Profit–oriented owners are less likely to produce high quality wines. These results suggest that the presence of hobbyists who enjoy producing high quality may lower financial returns in the segment and discourage profit–maximizers from locating there. 相似文献
58.
Drawing on qualitative data collected during semi-structured interviews with 36 profit centre managers in manufacturing firms in Victoria, Australia, this study seeks to explore the mechanisms used to manage multiple manufacturing performance dimensions arising from the pursuit of profit centre strategy. Where measures capture potentially conflicting influences on the manufacturing cost function, strategy implementation is facilitated by loosening control reactions to cost variances and through explicit attempts to integrate multiple measures. However, a joint emphasis on performance dimensions relating to manufacturing efficiency and customer responsiveness emerges as problematic. In contrast, a joint emphasis on quality and efficiency is relatively easily managed. It is suggested that in the context of responsiveness strategies, the difficulty of designing complete measures inhibits the effectiveness of performance measurement systems as a facilitator of strategy implementation. 相似文献
59.
Rolf Brühl Nils Horch und Mathias Orth 《Zeitschrift für Planung & Unternehmenssteuerung》2008,19(3):299-323
Zusammenfassung Die Bildung von Forschungshypothesen ist zwar immer ein kreativer, sollte aber gleichzeitig kein unsystematischer
Prozess sein. Im vorliegenden Artikel liegt der Fokus auf der Methodenunterstützung des Entdeckungszusammenhangs.
Die Methode der Grounded Theory bietet einen Bezugsrahmen für qualitative empirische Studien, mit dem
Theorien entwickelt werden, die aus dem Textmaterial zu begründen sind. Eine Literaturanalyse verdeutlicht,
dass das Potenzial dieser Methode bisher in der Controlling- und Rechnungswesenforschung weitgehend ungenutzt
bleibt. Anhand einer Diskussion empirischer Studien, welche auf die Methode zurückgreifen, werden
Anwendungsm?glichkeiten der Grounded Theory für diese Disziplinen aufgezeigt.
Summary Creating research hypotheses is always a creative but not necessarily an unsystematic process. In our study we introduce a method supporting the logic of discovery. The grounded theory approach provides a framework for a systematic development of theories emerging from empirical data. A literature review stresses that the potential of the method so far is unused in accounting research. The grounded theory approach is introduced to support empirical work within this research field. Options for an application of the method in accounting research are shown by the means of a discussion of empirical studies. Furthermore the reader gets hints for reference studies.相似文献
60.
E Persson M Ljunggren J la Cour Jansen R Strube L J?nsson 《Water science and technology》2006,53(12):139-147
A Discfilter with 10 and 18 microm filter openings, respectively, was placed in parallel to a flotation plant for separation of biological flocs from a post-denitrifying Kaldnes Moving Bed Process, the last treatment step at the municipal wastewater treatment plant at Sj?unda, Malm?, Sweden. The effluent concentrations from the 10 and 18 microm filter were 2-5 and 2-8 mg SS L(-1), respectively, which is comparable to, or better than, the flotation plant. Comparison with experiences from activated sludge plants shows that the Discfilter works especially well after the Kaldnes process. Particle size distribution (PSD) studies show that particles larger than the filter openings of 10 and 18 microm are separated with approximately 90% efficiency, whereas most of the smaller particles pass the filter. This fact indicates that the major particle separation mechanism is physical blocking. These findings point to the possibility of improving the prediction of the separation efficiency by combining measurements of turbidity and suspended solids with particle size analysis. 相似文献