近红外光谱检测技术在农业与食品分析中的应用分析

近红外光谱检测技术是当前较为常用的光谱分析技术,近年发展速度较快。近红外光谱具有操作简单、速度快、稳定性高、效率高的特点,在实际检测过程中不会对样品造成破坏,被广泛应用于各个领域。虽然我国在近红外光谱检测技术应用方面晚于西方国家,但是在某些方面的发展已经领先于国际水平。本文就如何充分利用现代网络技术,实现中心数据库和终端用户的资源共享,为有效推动近红外光谱技术的应用和发展提供参考。

Stability Analysis of Information Spreading on SNS Based on Refined SEIR Model

Investigating the stability of information spreading over SNS helps to understand the principles inherent in the spreading behavior.This paper explores the mechanisms of information spreading including stifling mechanism,latent mechanism and forgetting mechanism,establishes a refined SEIR model,and builds the corresponding mean-field equations.The methods of the differential dynamics and the next generation matrix are used to calculate the equilibriums and the basic reproductive number,and the asymptotical stability of the network equilibriums are proved theoretically.Simulation experiments are carried out to analyze the effect of the spreading mechanisms on the information spreading process and the results support our conclusions.

Security analysis of access control model in hybrid cloud based on security entropy

To resolve the problem of quantitative analysis in hybrid cloud,a quantitative analysis method,which is based on the security entropy,is proposed.Firstly,according to the information theory,the security entropy is put forward to calculate the uncertainty of the system' s determinations on the irregular access behaviors.Secondly,based on the security entropy,security theorems of hybrid cloud are defined.Finally,typical access control models are analyzed by the method,the method's practicability is validated,and security and applicability of these models are compared.Simulation results prove that the proposed method is suitable for the security quantitative analysis of the access control model and evaluation to access control capability in hybrid cloud.

Stability analysis and monitoring study of Jijia River landslide based on WebGIS

On the basis of in situ investigation and deformation monitoring of the Jijia River landslide （JJRL）, the rigid body limit equilibrium method and finite element method （FEM） were used to analyze the stability of the JJRL; the grey system theory method was applied to forecast the deformation trend of the JJRL; and the information system about the landslide deformation and monitoring, and forecasting systems based on the platform of the Web Geographical Information System （WebGIS） were developed, which can be used to analyze in situ monitoring data and predict the deformation of the landslide. The study results can be summarized as follows： （1） the JJRL is stable as a whole; the water content in the landslide has a great effect on its stability; （2） the developed Web Geographical Information System has realized many functions, including inputting, computing, inquiry, analyzing, and the function of forecasting; it has also realized the functions of distance data management, analysis, and forecasting based on the WebGIS; （3） the information resource can be shared by the WebGIS developed all over the world.

Quantitative comparison of similarity measure and entropy for fuzzy sets

Comparison and data analysis with the similarity measures and entropy for fuzzy sets were carried out. The distance proportional value between the fuzzy set and the corresponding crisp set was considered by the fuzzy entropy. The relation between the similarity measure and the entropy for fuzzy set was also analyzed. The fuzzy entropy was reformulated as the dissimilarity measure. Furthermore, crisp set having the minimum uncertainty with respect to the corresponding fuzzy set was also proposed. Finally, derivation of a similarity measure from entropy with the help of total information property was derived. A simple example shows the relation between similarity measure and fuzzy entropy, in which the summation of similarity measure and fuzzy entropy represents a constant value.

Vulnerability to Flood in the Vietnamese Mekong Delta： Mapping and Uncertainty Assessment

The Vietnamese Mekong Delta is located at the end of the Mekong River, one of the 10 largest rivers in the world. It plays an important role, especially in terms of food security for not only Vietnam but also the world. However, the Vietnamese Mekong Delta is projected to be heavily affected by： （1） the annual （fluvial） flood, which would be changed in terms of time and spatial distribution after impacts of climate change scenarios （i.e., sharper hydrograph with shorter flood period）; and （2） sea level rise. Such combination would result in significant changes of surface water resources, leading to consequent impacts on the existing fanning systems in the Vietnamese Mekong Delta. Therefore, this paper presents a new approach of integrating a one-dimensional hydrodynamic model （ISIS-1 D） with GIS （Geographic Information System ） analyses to： （1） identify priority areas for flood adaptation and mitigation; （2） provide an insight to local decision-makers in the Vietnamese Mekong Delta in changes of future floods.

Uncertainty and Sensitivity Analyses for Modeling Long-Term Soil Organic Carbon Dynamics of Paddy Soils Under Different Climate-Soil-Management Combinations

Reporting modeling results with uncertainty information can benefit decision making by decreasing the extent that variability exerts a disproportionate influence on the options selected. For making decisions with more confidence, the uncertainty interval should be as narrow as possible. Here, the soil organic carbon （SOC） dynamics of the major paddy soil subgroup from 4 different paddy field regions of China （located in 4 counties under different climate-soil-management combinations） were modeled using the DeNitrification- DeComposition （DNDC） model for the period from 1980 to 2008. Uncertainty intervals associated with the SOC dynamics for these 4 subgroups were estimated by a long-term global sensitivity and uncertainty analysis （i. e., the Sobolt method）, and their sensitivities to 7 influential factors were quantified using the total effect sensitivity index. The results, modeled with high confidence, indicated that in the past 29 years, the studied paddy soils in Xinxing, Yixing, and Zhongjiang counties were carbon （C） sinks, while the paddy soil in Helong County was a C source. The 3 C sinks sequestered 12.2 （5.4, 19.6）, 17.1 （8.9, 25.0）, and 16.9 （-1.2, 33.6） t C ha-1 （values in the parentheses are the 5th and 95th percentiles, respectively）. Conversely, the C source had a loss of -5.4 （-14.2, 0.06） t C ha-1 in the past 29 years. The 7 factors, which changed with the climate-soil-management context, exhibited variable influences on modeled SOC. Measures with potential to conserve or sequestrate more C into paddy soils, such as incorporating more crop residues into soils and reducing chemical fertilizer application rates, were recommended for specific soils based on the sensitivity analysis results.

A New Hybrid Reliability Index Definition and Its Application to the Structure Buckling Reliability Analysis of Supercavitating Projectiles

As structure buckling problems easily arise when supercavitating projectiles operate with high underwater velocity, it is necessary to perform structure buckling reliability analysis. Now it is widely known that probabilistic and non-probabilistic uncertain information exists in engineering analysis. Based on reliability comprehensive index of multi-ellipsoid convex set, probabilistic uncertain information is added and transferred into non-probabilistic interval variable. The hybrid reliability is calculated by a combined method of modified limit step length iteration algorithm(MLSLIA) and Monte-Carlo method. The results of engineering examples show that the convergence of MLSLIA is better than that of limit step length iteration algorithm(LSLIA). Structure buckling hybrid reliability increases with the increase of ratio of base diameter to cavitator diameter, and decreases with the increase of initial launch velocity. Also the changes of uncertain degree of projectile velocity and cavitator drag coefficient affect structure buckling hybrid reliability index obviously. Therefore, uncertain degree of projectile velocity and cavitator drag coefficient should be controlled in project for high structure buckling reliability.