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排序方式: 共有818条查询结果,搜索用时 15 毫秒
741.
Ass.-Prof. Dr. Wolfram Graf Univ.-Doz. Mag. Dr. Andreas Chovanec DI Dr. Severin Hohensinner DI Patrick Leitner DI Dr. Astrid Schmidt-Kloiber DI Dr. Ilse Stubauer ao.Univ.-Prof. Dr. Johann Waringer Mag. Gisela Ofenböck 《?sterreichische Wasser- und Abfallwirtschaft》2013,65(11-12):386-399
With the guideline 2000/60/EG, which called for the creation of a framework on water policy, the environmental policy of the European Community took on a new dimension. The goal of the guideline is (among others) the creation of a framework for the protection of inland surface waters, transitional waters, coastal waters and groundwater in order to avoid their deterioration; and to protect and improve the status of aquatic ecosystems, their associated land ecosystems directly dependent on them, and wetlands in terms of their water budget. Thanks to various forms of use, e.g. hydropower production, flood protection and ship traffic, especially major European rivers like the Danube, Rhine and Elbe have changed massively from their original typological characteristics. Reference conditions are hardly anywhere to be found, many native species are now extinct, and river biotopes are often dominated by invasive species. The size and depth of these rivers also pose challenges in terms of taking samples, and it has also become apparent that all methods currently used to assess rivers’ ecological status focus solely on the main channels; the various habitats to be found in large rivers’ riparian systems aren’t taken into account. However, there is international consensus that these systems are key elements in rivers’ processes and biodiversity, and as such are significant for the continuing functionality of major rivers. In the context of an Austrian Ministry of Life-funded research project, the Institute of Hydrobiology and Aquatic Ecosystem Management’s Working Group on Benthic Ecology and Ecological Status Assessment, together with the University of Vienna and the Environment Agency Austria, is currently working to develop a practice-oriented riparian zone index based on macrozoobenthos as an indicator of quality. To date, Europe has no Water Framework Directive-compliant assessment systems for riparian zones. Given the fact that established methods are limited to river’s main channels, precluding a holistic view of and approach to river ecosystems, this project represents a pioneering work in the field of European water resource management. 相似文献
742.
Johann Bizer 《Datenschutz und Datensicherheit - DuD》2008,32(12):818-825
DuD Recht
DuD Recht 相似文献743.
Stratego is a domain-specific language for the specification of program transformation systems. The design of Stratego is
based on the paradigm of rewriting strategies: user-definable programs in a little language of strategy operators determine
where and in what order transformation rules are (automatically) applied to a program. The separation of rules and strategies
supports modularity of specifications. Stratego also provides generic features for specification of program traversals.
In this paper we present a case study of Stratego as applied to a non-trivial problem in program transformation. We demonstrate
the use of Stratego in eliminating intermediate data structures from (also known as deforesting) functional programs via the warm fusion algorithm of Launchbury and Sheard. This algorithm has been specified in Stratego and embedded in a fully automatic transformation
system for kernel Haskell. The entire system consists of about 2600 lines of specification code, which breaks down into 1850
lines for a general framework for Haskell transformation and 750 lines devoted to a highly modular, easily extensible specification
of the warm fusion transformer itself. Its successful design and construction provides further evidence that programs generated
from Stratego specifications are suitable for integration into real systems, and that rewriting strategies are a good paradigm
for the implementation of such systems.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
744.
This work describes a new system using real time spectroscopic ellipsometer with simultaneous electrochemical and electrochemical quartz crystal microbalance (EQCM) measurements. This method is particularly adapted to characterize electrolyte/electrode interfaces during electrochemical and chemical processes in liquid medium. The ellipsometer, based on a rotating compensator Horiba Jobin-Yvon ellipsometer, has been adapted to acquire Psi-Delta spectra every 25 ms on a spectral range fixed from 400 to 800 nm. Measurements with short sampling times are only achievable with a fixed analyzer position (A=45 degrees ). Therefore the ellipsometer calibration is extremely important for high precision measurements and we propose a spectroscopic calibration (i.e., determination of the azimuth of elements according to the wavelength) on the whole spectral range. A homemade EQCM was developed to detect mass variations attached to the electrode. This additional instrument provides further information useful for ellipsometric data modeling of complex electrochemical systems. The EQCM measures frequency variations of piezoelectric quartz crystal oscillator working at 5 MHz. These frequency variations are linked to mass variations of electrode surface with a precision of 20 ng cm(-2) every 160 ms. Data acquisition has been developed in order to simultaneously record spectroscopic ellipsometry, EQCM, and electrochemical measurements by a single computer. Finally the electrodeposition of bismuth telluride film was monitored by this new in situ experimental setup and the density of electroplated layers was extracted from the optical thickness and EQCM mass. 相似文献
745.
Yuming Xu Jiangying Wu Tadek Dabros Hassan Hamza Sanyi Wang Marianne Bidal Johann Venter Tom Tran 《加拿大化工杂志》2004,82(4):829-835
Adding demulsifier is currently the most widely used method for breaking water‐in‐oil emulsions. Experimental demulsifiers based on DETA with various PO and EO contents were synthesized and their RSN values were determined. The dehydration efficiency of these demulsifiers was measured in diluted bitumen using both gravitational settling and centrifugation tests. The results indicate that some of the DETA products could perform potentially at least as well or better than the demulsifier currently used in a commercial plant. RSN values are correlated very well with EO and PO numbers. Optimal dehydration efficiency is in the RSN range of 18 to 22, which corresponds to a PO‐to‐EO ratio in the range of 1 to 1.8. 相似文献
746.
747.
Parosh Aziz Abdulla Johann Deneux Pritha Mahata 《Electronic Notes in Theoretical Computer Science》2005,138(3):117
We consider verification of safety properties for parameterized systems of timed processes, so called timed networks. A timed network consists of a finite state process, called a controller, and an arbitrary set of identical timed processes. In [Parosh Aziz Abdulla and Bengt Jonsson. Model checking of systems with many identical timed processes. Theoretical Computer Science, 290(1):241–264, 2003] it was shown that checking safety properties is decidable in the case where each timed process is equipped with a single real-valued clock. In [P. Abdulla, J. Deneux, and P. Mahata. Multi-clock timed networks. In Proc. LICS' 04, pages 345–354. IEEE Computer Society Press, 2004], we showed that this is no longer possible if each timed process is equipped with at least two real-valued clocks. In this paper, we study two subclasses of timed networks: closed and open timed networks. In closed timed networks, all clock constraints are non-strict, while in open timed networks, all clock constraints are strict (thus corresponds to syntactic removal of equality testing). We show that the problem becomes decidable for closed timed network, while it remains undecidable for open timed networks. We also consider robust semantics of timed networks by introducing timing fuzziness through semantic removal of equality testing. We show that the problem is undecidable both for closed and open timed networks under the robust semantics. 相似文献
748.
Triboelectric separation is a method for separating dry particulate systems due to their different electrostatic chargeability. Previous applications are limited to the separation of coarse powders. The aim of the present study is to examine the influence of the flow conditions and the influence of the electric field strength on the separation efficiency of starch and protein particles. Very fine organic powders are separated in a simple bench scale electrostatic separator to extend this technique to powders below 50?µm. The influence of different gas flow rates in the turbulent flow regime on particle charging and subsequent separation is investigated.As an organic model substrate, a mixture of barley starch and whey protein was used. The tribocharger consists of a PTFE charging tube and a rectangular separation chamber where an electric field is applied between two electrodes. The particles are conveyed through the charging tube and charged by frictional contact with the tube wall. It is shown that different gas flow rates at a turbulent flow regime in the charging tube did not change the separation characteristics. In contrast, increasing electrical field strength increases separation efficiency of protein particles regardless of gas flow conditions. The proportion of starch at the anode is the same for all the investigated parameters. 相似文献
749.
Angelika Mader Henrik Bohnenkamp Yaroslav S. Usenko David N. Jansen Johann Hurink Holger Hermanns 《International Journal on Software Tools for Technology Transfer (STTT)》2010,12(5):305-318
We treat the problem of generating cost-optimal schedules for orders with individual due dates and cost functions based on earliness/tardiness. Orders can run in parallel in a resource-constrained manufacturing environment, where resources are subject to stochastic breakdowns. The goal is to generate schedules while minimizing the expected costs. First, we estimate the distribution of each order type by simulation (assuming a reasonable machine/load model) and derive from the cost-function an optimal offset from the due date of each individual order. Second, these optimal offsets are then used to guide the generation of schedules which are responsible to resolve resource conflicts. Third, we evaluate the generated schedules by simulation. The approach is demonstrated by means of a non-trivial case-study from lacquer production. Optimal offsets are derived with the Modest/Möbius tool, schedules are generated using Uppaal Cora. The experimental results show that our approach achieves good results in all considered scenarios, and better results than an approach based on adding slack to processing times. 相似文献
750.
Marco E. T. Gerards Johann L. Hurink Philip K. F. Hölzenspies 《Journal of Scheduling》2016,19(1):3-19
Modern computers allow software to adjust power management settings like speed and sleep modes to decrease the power consumption, possibly at the price of a decreased performance. The impact of these techniques mainly depends on the schedule of the tasks. In this article, a survey on underlying theoretical results on power management, as well as offline scheduling algorithms that aim at minimizing the energy consumption under real-time constraints, is given. 相似文献