Theory of Vehicle's Durability Correlation Test

The theory of vehicle's correlation tests was discussed and the correlation test mathematical model was created. According to the damage theory, the correlation equation was brought up. The method to solove it was given. The text gives the theory basis of vehicle's correlation tests. The results can be used to give the vehicle's test designation and to make the test to fit the actual environments. Besides that, the methods give acceleration and strengthen effects.

Can environmental sustainability be decoupled from economic growth? Empirical evidence from Eastern Europe using the common correlated effect mean group test

The European Union(EU) and Organisation for Economic Co-operation and Development(OECD) aim to develop long-term policies for their respective member countries. Having observed increasing dangers to the environment posed by rising economic growth, they are seeking pathways to enable policy action on economic growth and environmental sustainability. Given the facts in theoretical and empirical studies, this study assessed the validity of the decoupling hypothesis by investigating asymmetricity in the relationship between environmental sustainability and economic growth in nine Eastern European countries from 1998 to 2017 using the cross-section augmented Dickey-Fuller(CADF) unit root, panel corrected standard error(PCSE), common correlated effect mean group(CCEMG), and Dumitrescu Hurlin causality approaches. Both population growth and drinking water are used as controlled variables. The outcomes establish strong cointegration among all the variables of interest. According to the results of CCEMG test, economic growth exerts short-term environmental degradation but has long-term environmental benefits in Eastern Europe;and population growth and drinking water exert a positive effect on environmental sustainability in both the short-and long-run. The results of Dumitrescu Hurlin causality test indicate that environmental sustainability is unidirectionally affected by economic growth. Based on these outcomes, we suggest the following policies:(1) the EU and OECD should implement member-targeted policies on economic growth and fossil-fuel use towards regulating industrial pollution, water use, and population control;and(2) the EU and OECD member countries should invest in environmental technologies through green research and development(R&D) to transform their dirty industrial processes and ensure productive energy use.

Correlation between indoor and outdoor corrosion tests for coal train body steel in a coal medium environment

Q345B carbon steel as well as Q450NQR1 and S500AW weathering steels were subjected to outdoor exposure corrosion tests in coal environments and indoor periodic immersion accelerated corrosion tests with a simulated coal leaching solution.The corrosion kinetics were studied by the weight loss method,and the corrosion morphology and corrosion product composition were observed and analyzed by scanning electron microscopy,energy-dispersive spectroscopy and X-ray diffraction.Afterward,correlation analysis of the indoor and outdoor tests was carried out by the gray correlation analysis method.The results show that the relationship between the corrosion weight loss and corrosion time of the three steels conforms to follow the exponent power law.In particular,Q450NQR1 steel has the best corrosion resistance.The types of corrosion products and the distribution of elements in the rust layer of the three steels are similar in the indoor and outdoor tests.The gray correlation degrees of the three steels in the indoor and outdoor tests are all greater than 0.6;thus,the two corrosion tests have a good correlation.Based on this,the accelerated simulation test method of the coal leaching solution is determined,and life prediction models of three steels in coal leaching solution are established to simulate the corrosion of the bottom board and side board.

Dynamic tensile characterization of pig skin

The strain-rate dependent response of porcine skin oriented in the fiber direction is explored under tensile loading. Quasi-static response was obtained at strain rates in the range of 10-3s-1to 25 s-1. Characterization of the response at even greater strain rates is accomplished by measuring the spatio-temporal evolution of the particle velocity and strain in a thin strip subjected to high speed impact loading that generates uniaxial stress conditions. These experiments indicate the formation of shock waves; the shock Hugoniot that relates particle velocity to the shock velocity and the dynamic stress to dynamic strain is obtained directly through experimental measurements, without any assumptions regarding the constitutive properties of the material.

Efficient Activation Method of Hardware Trojan Based on Greedy Algorithm

To generate test vector sets that can efficiently activate hardware Trojans and improve probability of the hardware Trojan activation,an efficient hardware Trojan activation method is proposed based on greedy algorithm for combinatorial hardware Trojans. Based on the greedy algorithm and the recursive construction method in the combination test,the method formulates appropriate and useful greedy strategy and generates test vector sets with different combinatorial correlation coefficients to activate hardware Trojans in target circuits. The experiment was carried out based on advanced encryption standard（ AES） hardware encryption circuit,different combinatorial hardware Trojans were implanted in AES as target circuits,the experiment of detecting hardware Trojans in target circuits was performed by applying the proposed method and different combinatorial hardware Trojans in target circuits were activated successfully many times in the experiment. The experimental results showthat the test vector sets generated using the proposed method could effectively activate combinatorial hardware Trojans,improve the probability of the hardware Trojan being activated,and also be applied to practice.

Low Cost Scan Test by Test Correlation Utilization

Scan-based testing methodologies remedy the testability problem of sequential circuits; yet they suffer from prolonged test time and excessive test power due to numerous shift operations. The correlation among test data along with the high density of the unspecified bits in test data enables the utilization of the existing test data in the scan chain for the generation of the subsequent test stimulus, thus reducing both test time and test data volume. We propose a pair of scan approaches in this paper; in the first approach, a test stimulus partially consists of the preceding stimulus, while in the second approach, a test stimulus partially consists of the preceding test response bits. Both proposed scan-based test schemes access only a subset of scan cells for loading the subsequent test stimulus while freezing the remaining scan cells with the preceding test data, thus decreasing scan chain transitions during shift operations. The proposed scan architecture is coupled with test data manipulation techniques which include test stimuli ordering and partitioning algorithms, boosting test time reductions. The experimental results confirm that test time reductions exceeding 97%, and test power reductions exceeding 99% can be achieved by the proposed scan-based testing methodologies on larger ISCAS89 benchmark circuits.

Inter-annual variations in vegetation and their response to climatic factors in the upper catchments of the Yellow River from 2000 to 2010

To understand the variations in vegetation and their correlation with climate factors in the upper catchments of the Yellow River, China, Normalized Difference Vegetation Index（NDVI） time series data from 2000 to 2010 were collected based on the MOD13Q1 product. The coefficient of variation, Theil–Sen median trend analysis and the Mann–Kendall test were combined to investigate the volatility characteristic and trend characteristic of the vegetation. Climate data sets were then used to analyze the correlation between variations in vegetation and climate change. In terms of the temporal variations, the vegetation in this study area improved slightly from 2000 to 2010, although the volatility characteristic was larger in 2000–2005 than in 2006–2010. In terms of the spatial variation, vegetation which is relatively stable and has a significantly increasing trend accounts for the largest part of the study area. Its spatial distribution is highly correlated with altitude, which ranges from about 2000 to 3000 m in this area. Highly fluctuating vegetation and vegetation which showed a significantly decreasing trend were mostly distributed around the reservoirs and in the reaches of the river with hydropower developments. Vegetation with a relatively stable and significantly decreasing trend and vegetation with a highly fluctuating and significantly increasing trend are widely dispersed. With respect to the response of vegetation to climate change, about 20–30% of the vegetation has a significant correlation with climatic factors and the correlations in most areas are positive： regions with precipitation as the key influencing factor account for more than 10% of the area; regions with temperature as the key influencing factor account for less than 10% of the area; and regions with precipitation and temperature as the key influencing factors together account for about 5% of the total area. More than 70% of the vegetation has an insignificant correlation with climatic factors.

Effects of Rainfall and Underlying Surface on Flood Recession——The Upper Huaihe River Basin Case

The effects of rainfall and underlying surface conditions on flood recession processes are a critical issue for flood risk reduction and water use in a region.In this article,we examined and clarified the issue in the upper Huaihe River Basin where flood disasters frequently occur.Data on 58 rainstorms and flooding events at eight watersheds during 2006–2015 were collected.An exponential equation(with a key flood recession coefficient)was used to fit the flood recession processes,and their correlations with six potential causal factors—decrease rate of rainfall intensity,distance from the storm center to the outlet of the basin,basin area,basin shape coefficient,basin average slope,and basin relief amplitude—were analyzed by the Spearman correlation test and the Kendall tau test.Our results show that 95%of the total flood recession events could be well fitted with the coefficient of determination(R2)values higher than 0.75.When the decrease rate of rainfall intensity(Vi)is smaller than 0.2 mm/h2,rainfall conditions more significantly control the flood recession process;when Vi is greater than 0.2 mm/h2,underlying surface conditions dominate.The result of backward elimination shows that when Vi takes the values of0.2–0.5 mm/h2 and is greater than 0.5 mm/h2,the flood recession process is primarily influenced by the basin’s average slope and basin area,respectively.The other three factors,however,indicate weak effects in the study area.

A novel multi-level model for quasi-brittle cracking analysis with complex microstructure

The paper presents a novel multi-level model for quasi-brittle cracking analysis.Based on the partition of unity and information transmission technology,it provides a new non-re-meshing way to describe the cracking phenomenon in structures constructed from materials with complex microstructures.In the global model,the concept of the material particle is defined and the basic unknowns are the boundary displacements of these particles,which is different from the concept of the traditional displacement field.A series of enrichment functions with continuous steps is proposed,describing the boundary displacement affected by crack bands and allowing the intersections of crack bands with particle boundaries a priori unknown.Simultaneously,additional equations are introduced to determine element status and make the degrees of freedom of the global model remain at a stable level.Compared with previous research by our group,where the local description is equal to the global description on the boundary of a material particle,the introduced enrichment functions enable more accurate capture of the characteristics of the crack band.The model avoids the complex and dynamic model adjustments due to the activation and exit of representative volume elements(RVEs)and the accuracy of the description of the crack pattern can be ensured.The RVEs are activated at first,but then many of them exit the computation due to the unloading which reduces many of the degrees of freedom.Two examples of concrete specimens are analyzed,and the concrete fracture experiment and the digital image correlation(DIC)test are conducted.Compared with the reference solutions and the experimental data,even though the microstructure of concrete is very complex,the cracking process and crack pattern can be obtained accurately.