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排序方式: 共有142条查询结果,搜索用时 15 毫秒
1.
Relating Sediment Yield Estimations to the Wet Front Term Using Rainfall Simulator Field Experiments
Norouzi-Shokrlu Akbar Pajouhesh Mehdi Abdollahi Khodayar 《Water Resources Management》2020,34(13):4181-4196
Water Resources Management - Depth to wet front is generally considered as the amount of water that penetrates into soil and wets the internal soil layer. This is an important variable especially... 相似文献
2.
A Wavelet-ANFIS Hybrid Model for Groundwater Level Forecasting for Different Prediction Periods 总被引:8,自引:2,他引:6
Vahid Moosavi Mehdi Vafakhah Bagher Shirmohammadi Negin Behnia 《Water Resources Management》2013,27(5):1301-1321
Artificial neural network (ANN) and Adaptive Neuro-Fuzzy Inference System (ANFIS) have an extensive range of applications in water resources management. Wavelet transformation as a preprocessing approach can improve the ability of a forecasting model by capturing useful information on various resolution levels. The objective of this research is to compare several data-driven models for forecasting groundwater level for different prediction periods. In this study, a number of model structures for Artificial Neural Network (ANN), Adaptive Neuro-Fuzzy Inference System (ANFIS), Wavelet-ANN and Wavelet-ANFIS models have been compared to evaluate their performances to forecast groundwater level with 1, 2, 3 and 4 months ahead under two case studies in two sub-basins. It was demonstrated that wavelet transform can improve accuracy of groundwater level forecasting. It has been also shown that the forecasts made by Wavelet-ANFIS models are more accurate than those by ANN, ANFIS and Wavelet-ANN models. This study confirms that the optimum number of neurons in the hidden layer cannot be always determined by using a specific formula but trial-and-error method. The decomposition level in wavelet transform should be determined according to the periodicity and seasonality of data series. The prediction of these models is more accurate for 1 and 2 months ahead (for example RMSE?=?0.12, E?=?0.93 and R 2?=?0.99 for wavelet-ANFIS model for 1 month ahead) than for 3 and 4 months ahead (for example RMSE?=?2.07, E?=?0.63 and R 2?=?0.91 for wavelet-ANFIS model for 4 months ahead). 相似文献
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Mehdi Ahmadi Masood Khodadadi Himan Shahabi 《Journal of Quality Assurance in Hospitality & Tourism》2018,19(2):243-268
ABSTRACTThis paper reports a study of the Manesht- and Ghelarang-protected area in Iran. The study sought to identify ways in which sustainable tourism policies could be generated that aid the natural and human environments. From surveys and questionnaires completed by tourists, residents, and officials, an initial set of 10 areas of weakness, 9 strengths, and 6 opportunities were identified. Using these classifications combined with mapping techniques that included maps of topography and flora, a subsequent Technique for Order of Preference by Similarity to Ideal Solution analysis identified potential future policies that require infrastructure development and reinforced pro-environmental policies to address the problems currently being experienced. 相似文献
6.
Clare DSouza Mehdi Taghian Peter Lamb Roman Peretiatko 《International Journal of Consumer Studies》2007,31(4):371-376
This research examined the demographic profiles of Australian green consumers in relation to their satisfaction of environmental labelling. It examined consumers’ understanding of labelling and empirically investigated the association of demographic profile of consumers with their attitudes towards such labels. The results indicated that some of the demographic variables were significant, which is largely consistent with earlier findings by other researchers in this area. Label dissatisfaction was higher in the older and middle age respondents. However, some respondents disagreed that labels were accurate while commenting that labels were easy to understand. The key issue arising from the findings is that in order to provide perception of accuracy in labels, it is an option to use Type I or Type III labelling on products. These labels are, arguably, more credible because they are endorsed by third party labelling experts. This would come at a cost and for green products that use third party labelling, they will also have to bear in mind to keep the prices competitive. 相似文献
7.
Mehdi Boussebaa Andrew Sturdy Glenn Morgan 《International Journal of Human Resource Management》2013,24(9):1227-1242
This paper examines the nature of the contemporary multinational corporation (MNC) through a study of the use of knowledge management systems (KMS) in four major international consulting firms. In particular, we explore whether and how such systems facilitate horizontal (inter-subsidiary) flows of knowledge, as described in the network view of the MNC. Our analysis reveals the presence of horizontal flows within the four firms, but flows that are contextually constrained and partly shaped by geopolitical power relations. Thus, our study gives some support to the image of the MNC as a network whilst highlighting the contextual limits of horizontal knowledge transfer and, importantly, the geopolitical conditions under which such knowledge transfer takes place. At the same time, it challenges the claim that consulting firms are model organizations in the area of knowledge management as well as the more negative view that questions the ability of KMS to facilitate knowledge transfer. 相似文献
8.
Farjadfard S Borghei SM Hassani AH Yakhchali B Ardjmand M Zeinali M 《Water science and technology》2012,66(3):594-602
A bacterial strain, FBHYA2, capable of degrading naphthalene, was isolated from the American Petroleum Institute (API) separator of the Tehran Oil Refinery Complex (TORC). Strain FBHYA2 was identified as Achromobacter sp. based on physiological and biochemical characteristics and also phylogenetic similarity of 16S rRNA gene sequence. The optimal growth conditions for strain FBHYA2 were pH 6.0, 30 °C and 1.0% NaCl. Strain FBHYA2 can utilize naphthalene as the sole source of carbon and energy and was able to degrade naphthalene aerobically very fast, 48 h for 96% removal at 500 mg/L concentration. The physiological response of Achromobacter sp., FBHYA2 to several hydrophobic chemicals (aliphatic and aromatic hydrocarbons) was also investigated. No biosurfactant was detected during bacterial growth on any aliphatic/aromatic hydrocarbons. The results of hydrophobicity measurements showed no significant difference between naphthalene- and LB-grown cells. The capability of the strain FBHYA2 to degrade naphthalene completely and rapidly without the need to secrete biosurfactant may make it an ideal candidate to remediate polycyclic aromatic hydrocarbon (PAH)-contaminated sites. 相似文献
9.
We evaluate the relationship between the appointment of women to CEO or Chair positions and firm performance, and shed light on the differences between family and nonfamily firms. By using a propensity score matching approach on a sample of 394 French firms over the period 2001–2010, we find major discordances between women’s leadership style and family business expectations relative to firm performance, as measured by return on assets and Tobin’s q. Notably, our results support the conjecture that family firms, which are more conducive to transformational leadership, offer women a more appropriate climate for exercising the function of Chair than that of CEO. In contrast, women CEOs perform better in nonfamily firms. Our findings move away from the predominant focus on barriers and stereotypes images about the female leadership and support the contingency theory of leadership, which states that the effectiveness of a leadership style depends on the organization and culture in which leaders operate, and on task-related positions 相似文献
10.
This article has attempted to examine the impact of motivation on the purchasing and represents a model for organic or local cucumbers buying dimensions. Data were collected by a sample of 300 people in two northern provinces of Iran during 7 months and were tested using structural equation modeling (SEM) technique. Results indicate that not using pesticides, preserving people’s health, conservation, better taste, and region of origin of organic or local cucumbers have significant positive impacts on purchasing dimensions and persistence has no significant effect on purchasing dimensions. 相似文献