scholarly journals Community and programmatic factors influencing effective use of system dynamic models

2018 ◽  
Vol 34 (1-2) ◽  
pp. 154-171 ◽  
Author(s):  
Karen Minyard ◽  
Tina A. Smith ◽  
Richard Turner ◽  
Bobby Milstein ◽  
Lori Solomon
Author(s):  
Yawen Wang ◽  
Junyi Yang ◽  
Dong Guo ◽  
Teik C Lim

A generalized dynamic model of driveline system is formulated that includes the coupling effect and gyroscopic moments of the propeller shaft and hypoid gear rotor assembly. Firstly, the dynamic models with only gear-shaft coupling, with only gyroscopic effect, and with both gear-shaft coupling and gyroscopic effect are analyzed and compared. The results show that the combined effects of the gear-shaft interaction and gyroscopic behavior have considerable influence on the system dynamic responses surrounding gear bending resonances, especially for the bearing responses. However, the gear out-of-phase torsional modes still dominate the gear mesh frequency response. Secondly, the influence of pinion bending moment of inertia, propeller shaft stiffness and bearing stiffness on the system dynamic responses are examined. The system responses are then applied to perform further vibration and acoustic analysis for an axle housing structure. Computational results reveal that NVH (noise, vibration, and harshness) refinement can be achieved by tuning the pinion bearing rotational stiffness and pinion bending moment of inertia for the example considered. This study provides an understanding of the interaction between hypoid gear pair and propeller shaft, and can be employed to enhance driveline system design.


Water ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 189
Author(s):  
Lili Yang ◽  
Tong Heng ◽  
Guang Yang ◽  
Xinchen Gu ◽  
Jiaxin Wang ◽  
...  

The factors influencing the effective utilization coefficient of irrigation water are not understood well. It is usually considered that this coefficient is lower in areas with large-scale irrigation. With this background, we analyzed the effective utilization coefficient of irrigation water using the analytic hierarchy process using data from 2014 to 2019 in Shihezi City, Xinjiang. The weights of the influencing factors on the effective utilization coefficient of irrigation water in different irrigation areas were analyzed. Predictions of the coefficient’s values for different years were made by understanding the trends based on the grey model. The results show that the scale of the irrigation area is not the only factor determining the effective utilization coefficient of irrigation water. Irrigation technology, organizational integrity, crop types, water price management, local economic level, and channel seepage prevention are the most critical factors affecting the effective use of irrigation water. The grey model prediction results show that the effective utilization coefficient of farmland irrigation water will continuously increase and reach 0.7204 in 2029. This research can serve as a reference for government authorities to make scientific decisions on water-saving projects in irrigation districts in terms of management, operation, and investment.


1976 ◽  
Vol 66 (1) ◽  
pp. 281-324 ◽  
Author(s):  
Jack F. Evernden

abstract This paper discusses seismological aspects of various proposed means of obscuring or hiding the seismic signatures of explosions from a surveillance network. These so-called evasion schemes are discussed from the points of view of both the evader and the monitor. The analysis will be conducted in terms of the USSR since that country is so vast and its geological and geophysical complexities are so great that the complete spectrum of hypothesized evasion schemes requires discussion. Part I of this paper was a general discussion of these evasion schemes, placing the concepts within the reality of general factors influencing effective use of the techniques. This part of the paper (part II) describes techniques for quantitative investigation of evasion schemes when the only noise problem is normal microseismic noise, and will give analyses of several seismological networks as regards their capabilities to restrain imagined clandestine testing by the USSR under such noise conditions. Part III will describe techniques appropriate for use when the noise problem is the P- and surface-wave codas of earthquakes, and will give analyses of capabilities of several seismological networks to restrain use of such codas for effective evasion.


2021 ◽  
Author(s):  
Giorgos Maneas ◽  
Erasmia Kastanidi ◽  
Ioannis Panagopoulos

<p>The EUs Water Framework Directive, was adopted on October 2000, and it has been the basis for water management in all the EU countries since then (EU-WFD, 2000). According to the EUs-WFD, the use of groundwater bodies can be considered as sustaibale only when the portion of the overall recharge not needed by the ecology is abstracted (EU-WFD, 2000). Nonetheless, there are still cases where the implementation of the EUs-WFD faces challenges, and there is a need to better communicate the above message to water users. But how can we achieve this at a local scale?</p><p>In this work, we present the example of SW Messinia, Greece, an interlinked coastal-inland area in the Eastern Mediterranean region. In this case study, the water supply for all water uses (agriculture, tourism, domestic use) depends on groundwater resources which are also the main freshwater provider to a coastal wetland with high ecological and commercial value (Birds directive 2009/147/EC; Habitats Directive 92/43/EEC). Due to man-made interventions over the last 70 years, the wetland has passed the tipping point of being brackish (Maneas et al., 2019), and at present it is characterized as saline with hypersaline conditions for nearly 30% of the year (Manzoni et al., 2020). Unless freshwater inputs are enhanced by restoring hydrologic connectivity between the wetland and the surrounding freshwater bodies, salinity in the lagoon is expected to increase even more under future drier and warmer conditions (Manzoni et al., 2020). But how can we balance between societal and ecological groundwater needs, and how future decision making can get a broader acceptance by the society?</p><p>Under COASTAL EU project (COASTAL, 2019), we use System Dynamic (SD) models for communicating with local stakeholders towards improving land-sea interactions. In this work, we present a model which describes how inland groundwater abstraction has impacts to the wetland’s salinity. The model is used as a basis for a discussion with stakeholders and the co-creation of sustainable decision making with broader acceptance.</p><div>Literature<br><div> <p>EU WFD, 2000. Available at: https://ec.europa.eu/environment/water/water-framework/index_en.html (Accessed on 20-01-2021).</p> <p>Birds Directive 2009/147/EC (2009). The European Union Birds Directive. Available online at: https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=<br>CELEX:32009L0147 (accessed November 2, 2020) .</p> <p>Habitats Directive 92/43/EEC (1992). The European Union Habitats Directive. Available online at: https://ec.europa.eu/environment/nature/legislation/<br>habitatsdirective/index_en.htm (accessed September 2, 2019).</p> <p>Maneas, G., Makopoulou, E., Bousbouras, D., Berg, H., and Manzoni, S. (2019). Anthropogenic changes in a Mediterranean coastal wetland during the last century-the case of Gialova Lagoon, Messinia, Greece. Water 11:350. doi: 10.3390/w11020350 </p> <p>Manzoni, S., Maneas, G., Scaini, A., Psiloglou, B. E., Destouni, G., and Lyon, S. W. (2020). Understanding coastal wetland conditions and futures by closing their hydrologic balance: the case of Gialova Lagoon, Greece. Hydrol. Earth Syst. Sci. 24, 3557–3571. doi: 10.5194/hess-24-3557-2020</p> <p>Maneas G, Bousbouras D, Norrby V and Berg H (2020). Status and Distribution of Waterbirds in a Natura 2000 Area: The Case of Gialova Lagoon, Messinia, Greece. Front. Ecol. Evol. 8:501548. doi: 10.3389/fevo.2020.501548</p> <p>COASTAL [Collaborative Land-Sea Integration Platform] (2019). European Union’s H2020 Research and Innovation Programme Under Grant Agreement No. 773782. Available online at: https://h2020-coastal.eu/ (accessed 03 February, 2019).</p> </div> </div>


2015 ◽  
Vol 1084 ◽  
pp. 678-683
Author(s):  
Oleg P. Savitsky ◽  
Valeriy F. Dyadik ◽  
Oksana P. Kabrysheva

This paper is devoted to one of the most urgent problems in the automation of fluorine production (FP) processes: the development of a dynamic model of the hydrodynamic regime. The paper suggests a dynamic model represented in the form that provides the effective use of up-to-date methods of synthesis and analysis for control algorithms. The model is a set of dynamic models of individual units and devices that have a significant impact on the processes in the technological scheme.


Mechatronics ◽  
1998 ◽  
Vol 8 (3) ◽  
pp. 255-270 ◽  
Author(s):  
Amuliu Bogdan Proca ◽  
Ali Keyhani

Sign in / Sign up

Export Citation Format

Share Document