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We investigate the experimental frame concept for discrete event simulation. We first give a brief history of experimental frames and then present and discuss the desired properties of a modern approach to experimental frames. Lastly, we describe the experimental frames implemented in the Hierarchical Modeling and Simulation System-Java (HiMASS-j). HiMASS-j is a prototype modeling and simulation system that uses the Hierarchical Control Flow Graph Model paradigm, visual interactive modeling, and the modern approach to experimental frames. 相似文献
74.
aDORe: A Modular, Standards-Based Digital Object Repository 总被引:4,自引:0,他引:4
75.
Thorsten Helbig Kay Unterer Christian Kulas Sergej Rempel Josef Hegger 《Beton- und Stahlbetonbau》2016,111(10):676-685
Pedestrian bridge made from carbon‐concrete in Albstadt‐Ebingen – First entirely carbon‐reinforced concrete bridge worldwide The bridge erected in Albstadt‐Ebingen in October 2015 is realized without any steel reinforcement or pre‐tensioning, making it the world's first entirely carbon‐reinforced concrete bicycle and pedestrian‐bridge. The trough section with material thicknesses of 70 mm (trough walls) and 90 mm (slab) respectively has been fabricated as monolithic pre‐cast element. With a span length of 15 m and a width of 3 m, the bridge‐deck requires no further coating and has a total weight of just 14 tons (approximately 310 kg/m2); this is about 50 % of comparable conventional reinforced concrete bridge‐decks. Besides material and weight savings, an exceptionally long service life with minimal maintenance can be expected, as the steel corrosion that is typical in reinforced concrete structures can be entirely avoided. Since the use of carbon‐reinforced concrete (carbon concrete) is not yet approved in Germany, the client had to obtain approval based on individual cases (ZiE). 相似文献
76.
Tits J Stumpf T Rabung T Wieland E Fanghänel T 《Environmental science & technology》2003,37(16):3568-3573
The interaction of the two chemical homologues [Cm(III) and Eu(III)] with calcium silicate hydrates (CSH phases) at pH 13.3 has been investigated in batch-type sorption studies using Eu(III) and complemented with time-resolved laser fluorescence spectroscopy (TRLFS) using Cm(III). The sorption data for Eu(III) reveal fast sorption kinetics and a strong uptake by CSH phases with distribution ratios of (6 +/- 3) x 10(5) L kg(-1). Three different Cm(III) species have been identified: A nonfluorescing species, which was identified as a curium hydroxide (surface) precipitate, and two fluorescing Cm(III)/CSH-sorbed species. The fluorescing sorbed species have characteristic emission spectra with main peak maxima at 618.9 and 620.9 nm and fluorescence emission lifetimes of 289 +/- 11 and 1482 +/- 200 micros, respectively. From the fluorescence lifetimes, it was calculated that the two fluorescing Cm(III) species have one or two and no water molecules left in their first coordination sphere, suggesting that these species are incorporated into the CSH structure. A structural model for Cm(III) and Eu(III) incorporation into CSH phases is proposed based on the substitution for Ca at two different types of sites in the CSH structure. 相似文献
77.
Tauer A Bender TO Fleischmann EH Niwa T Jörres A Pischetsrieder M 《Molecular nutrition & food research》2005,49(7):710-715
Conventional fluids for peritoneal dialysis (PD) contain reactive glucose degradation products (GDPs) as a result of glucose breakdown during heat-sterilization. GDPs in PD fluids (PDFs) have been associated with the progressive alteration of the peritoneal membrane during long-term PD by cytotoxic effects and formation of advanced glycation endproducts (AGEs). In this study, we investigated the possible fate of two characteristic GDPs, 3-deoxyglucosone (3-DG) and glyoxal, during PD. In vivo, 3-DG and glyoxal concentrations, which were analyzed by high-performance liquid chromatography (HPLC), decreased in PDFs by 78% and 88% during 4 h of dwell time. The PDFs were then incubated in vitro in the presence of the most important reaction partners of GDPs in the peritoneal cavity. Neither human peritoneal mesothelial cells, human peritoneal fibroblasts, soluble protein, an insoluble collagen surface, nor components of spent dialysate led to a significant reduction of 3-DG or glyoxal after 6 h. Only after long-term incubation, a noticeable decrease of 3-DG was observed (-37% after three weeks), more likely due to spontaneous degradation reaction than formation of advanced glycation endproducts. These results suggest that in the course of PD, 3-DG, and glyoxal are absorbed into the organism and thus might contribute to the systemic pool of reactive carbonyl compounds. 相似文献
78.
Supply chain management has both in academia and practice proven its important role to sustain and further develop companies’ competitive advantages. This is with initiatives that focus on cost-efficiencies and turnover improvement. During the last two decades, companies have faced complexity in their supply chains currently with increased global operations. The dynamic business environment forces companies to secure a competitive (re-) design of their supply chains. This paper seeks to advance the understanding on the drivers and barriers for such designs. In total, 39 experts (30 from industrial enterprises, 4 senior supply chain consultants and 5 supply chain management professors) have participated in a four-step Delphi study and have identified main drivers for dynamic supply chain design as being cost reduction, delivery reliability and change in demand for agility. The main barriers are identified as forecasting being too weak, supply chain complexity and product portfolio complexity. In addition, an explorative factor analysis has been carried out to identify how drivers and barriers can be grouped together. Finally, the paper compares the drivers and barriers underlining different competitive strategies. 相似文献
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80.
Prof. Dr.-Ing. Thorsten Spitta Dipl. Ing. Helmut Schmidpeter 《WIRTSCHAFTSINFORMATIK》2002,44(2):141-150
This paper analyses the characteristics of software houses as service providers. The tasks of internal IT-services are determined from these characteristics and a reporting system for the IT-controlling is outlined. The concept results from the analysis of one of the 25 largest German software houses. The paper concludes with a case study of the fiscal year 2000 IT-controlling report of the above-mentioned firm. 相似文献