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Copyright of Food Research & Development is the property of Food Research & Development Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

One kind of Q-precentile life prediction method for gear pumps with small sample sizes was proposed based on bivariate Wiener process. The degradation processes of volume efficiency and total efficiency for gear pumps were modeled by Wiener process with random effects, and the fluctuation of gear pump performance characteristics with time and individual differences were characterized. The appropriate Copula function was selected to describe the correlation between the two degradation performance characteristics based on Akaike Information criterion (AIC). A bivariate degradation model was established and the unknown parameters of the model were estimated by Markov chain Monte Carlo (MCMC) method. The Bootstrap sampling method was used to re-sample the parameters representing individual differences by considering the facts that the performance degradation test of gear pumps was usually a small sample size. Finally, through gear pump performance degradation tests, the Q-precentile life prediction was realized, and the validity and accuracy of the proposed method were verified. The testing results show that there is a nonlinear correlation between the two characteristics in the degradation processes. Q-precentile life prediction considering correlation is more conservative than single feature prediction, and is more affected by the performance characteristics that first reach the failure threshold. [ABSTRACT FROM AUTHOR]

Copyright of Clean Coal Technology is the property of Clean Coal Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The rural landscape function has obvious temporal and spatial heterogeneity, and exploring the relationship between landscape functions has become the focus of landscape ecology research. Aiming at the scientific representation of landscape function and the quantification of landscape multifunctional relationship, taking Qingpu district of Shanghai as an example, 6 kinds of landscape functions were constructed according to the functional framework of “production, life and ecology”. Based on the data from 1980 to 2015, the variation characteristics of multi-functional trade-off and synergy relationships of rural landscape in 184 administrative villages in this area were studied by using the method of Spearman rank correlation coefficient analysis and bivariate spatial autocorrelation. The following results are obtained: 1) the agricultural production function of urban suburbs cannot replace the function of economic development. The economic development function of Qingpu district has become the leading functional. 2) The spatial and temporal differences of the multi-functional trade-off and synergy relationships of rural landscape in Qingpu district from 1980 to 2015 were significant. The production function- living function is led by the cooperative relationship, the space was spread along the central axis, the production function- ecological function was dominated by the trade-off relationship, the space was spread from the middle to the east, and the living function -ecological function trade-off the cooperative relationship was more balanced, The trade-off relationship was spread from the middle to the east and the synergy was spread from the west to the north and south. The contradiction between agricultural production function - economic development function (EDF), economic development function- ecological regulation function (ERF)/ environmental maintain function (EMF) was the inevitable contradiction in this area, and the economic development of this area was realized at the expense of ecological environment. There was a significant trade-off relationship between the EDF and landscape aesthetic function (LAF), and the pattern of the relationship between the two was the synergy of the eastern trade-off west, and the number of weighing areas was increasing. The relationship between EDF and spatial bearing function presents the pattern of eastern trade-off and western coordination, and the cooperative relationship area showed an increasing trend. The trade-off area between LAF-ERF/EMF was concentrated in Qingdong area, and the cooperative area was distributed in Qingxi area, and the number of weighing area increases at first and then decreases. The synergy area decreases at first and then increases. 3) The analysis method of temporal and spatial combination can accurately and comprehensively reflect the evolution characteristics of multi-functional trade-offs & synergies relationships of multifunctional rural landscape. The correlation analysis of multi-function and single time dimension of rural landscape cannot fully and accurately represent the change of multi-functional relationship, and there are differences in the pattern of space-time relationship. The relationship between spatial carrying function and ecological regulation function/environmental balance function was found to be compatible in time and tradeoff in space. And the results of time synergy and spatial tradeoff between agricultural production function and ecological regulation function/environmental balance function verify the scientific nature of using space-time model to analyze the multi-function tradeoff-synergy relationship of rural landscape. [ABSTRACT FROM AUTHOR]

The middle and lower reaches of the Yangtze River serves as an important grain production base in China. In the context of global climate change, the drought events will directly affect the agriculture production and people's properties and lives in this region and also the national food security. In this study, the meteorological drought events have been extracted using run theory based on the standardized precipitation index (SPI), which is defined using the gridded dataset of monthly precipitation with a spatial resolution of 0.5° × 0.5° in China from 1961 to 2015. The drought events are characterized by three variables including duration, severity and peak. Exponential and Gamma functions are then selected to describe the marginal distribution of drought duration and severity, respectively. The Clayton Copula is used to construct the joint distribution of drought duration and severity. Based on the above functions, conventional univariate frequency analysis and copula- based bivariate frequency analysis are used to characterize the spatial patterns of the drought events in the study area at various time scales over the past 55 years. While univariate analysis is focused on return levels of selected return periods (5-, 10-, 20-, and 30-year) for the SPI of 3-, 6-, and 12-month time scales, the bivariate analysis is focused on the joint occurrence probabilities P1 and P2 of drought duration and severity, where P1 is the probability of "drought duration and severity" exceeding their respective thresholds at the same time and P2 is the probability of "drought duration or severity" exceeding their respective thresholds at the same time. Here, the thresholds denote the duration and severity values corresponding to selected 5-, 10-, 20- and 30- year return periods. The results show that: (1) There are some differences between the spatial patterns of drought characteristics for the 3- month, 6- month, 12- month time scales in the middle and lower reaches of the Yangtze River, and the most serious droughts mainly occur in the lower reaches of the river. (2) Both drought duration and severity are positively correlated at various time scales, that is, the areas with higher drought severity are also associated with longer drought duration and vice versa. (3) Poyang Lake watershed and areas north of the lower Yangtze River are associated with larger values of the joint occurrence probability P1, that is, when the drought duration and severity exceed their corresponding 5, 10, 20 and 30- year return values at the same time, while smaller values of the joint occurrence probability P1 are noted for Southern Shaanxi, Southern Henan, a major portion of Hubei and central-north of Hunan, suggesting a low risk of droughts in these areas. The results of this study can provide theoretical basis for scientific managements of water resource and the risk assessments of drought disaster in the middle and lower reaches of the Yangtze River. [ABSTRACT FROM AUTHOR]

Researching the governance role of independent directors on the network view is an updated field of corporate governance. Using the Bivariate Probit model, this study investigates the influence of network position of independent directors on corporate violation of rules. Independent directors with rich network relationships can possess more social capital to improve their motivation and ability of monitoring, which will reduce the possibility of corporate violation of rules. Consistent with theoretical analysis, the result shows that the network centrality of independent directors has significantly negative relationship with the propensity of corporate violation of rules. The study reveals that network of independent directors has positive influence on their monitoring roles. The complementary tests show that the active effect of independent director networks exists in the aspect of information disclosure fraud, but not in the aspect of other kinds of fraud; networks of independent directors entering audit committees have active effect, but others have not; the active effect of independent director networks is more significant in firms with worse profitability. This paper complements the literature of independent directors, board networks and corporate violation of rules. [ABSTRACT FROM AUTHOR]