Research on the economic effect of employment structure change in heterogeneous regions: evidence from resource-based cities in China

The Report on the Work of the Chinese Government in 2021 emphasised that stable employment is the foundation of national development. Therefore, adjustment of the employment structure is one of the main routes for sustainable development of resource-based cities. However, the impact of employment structure on sustained economic growth, particularly in heterogeneous regions, has not yet been determined. This study analyses China’s employment structure’s spatial evolution, using panel data from 2004 to 2018 of 115 prefecture-level resource-based cities. It explores the driving factors and spatial effects of employment structure changes on economic growth through an extended two-sector economic growth model and spatial econometric model, and proposes solutions for heterogeneous regions. The results show that the labour productivity of the employed population in the secondary industry is the most important factor affecting economic growth, but the spatial effects of employment structure adjustment on economic growth are different in heterogeneous regions. They further reveal that improving the productivity of the employed population in the secondary industry and building an industrial system according to regional advantages are the top priorities for developing the sustainable economy of resource-based cities

Estimation of nitrogen in cotton leaves using different hyperspectral region data

As an important index of a plant’s N nutrition, leaf nitrogen content (LNC) can be quickly monitored in real time with hyperspectral information, which is helpful to guide the precise application of N in cotton leaves. In this study, taking cotton dripping in Xinjiang, China, as the object of study, five N application treatments (0, 120, 240, 360, 480 kg·ha-1) were set up, and the hyperspectral data and the N content of main stem functional leaves at the cotton flower and boll stage were collected. The results showed that (1) comparing the correlations of the three types of spectral data from the original spectra, first derivative spectra, and second derivative spectra with the LNC of cotton, the first derivative spectra increased the correlation between the reflectance in the peak and valley ranges of the spectral curves and the LNC of cotton; (2) in the three hyperspectral regions of VIS, NIR, and SWIR, all R2 values of the estimation model for the LNC of cotton established based on the characteristic wavelengths of the original and the first derivative spectra were greater than 0.8, and the model accuracy was better than that of the second derivative spectra; and (3) the normalized root mean square error (n-RMSE) values of the validated model using MLR, PCR, and PLSR regression methods were all in the range of 10–20%, indicating that the established model could well estimate the nitrogen content of cotton leaves. The results of this study demonstrate the potential of the three hyperspectral domains of VIR, NIR, and SWIR to estimate the LNC of cotton and provide a new basis for hyperspectral data application in crop nutrient monitoring

Validation of behavioral hardware descriptions

Behavioral hardware descriptions are commonly used to represent the functionality of a microelectronic system for simulation and synthesis. The manual process of creating a behavioral description is prone to errors, so a significant effort must be made to verify the correctness of the behavioral descriptions. Simulation-based validation and formal verification are two techniques used to verify correctness of designs. We have investigated validation because formal verification techniques are frequently intractable for large designs. The first step toward a behavioral validation technique is the development of validation fault coverage metrics which can be used to evaluate the likelihood of design error detection with a given test sequence. Design faults can be classified into a variety of classes. The hardest faults are those which present incorrect behavior only in rare corner cases. We developed three fault coverage metrics to target these corner case faults. First, the domain fault coverage detects faults on the domain boundaries by examining the test points near the boundaries since a small domain fault may only affect several points near the boundary. Second, the dataflow fault coverage metric systematically checks the coverage of selected dataflow paths, which can detect faults associated with the dataflow paths. Third, the mis-timed event (MTE) fault coverage metric detects faults that present erroneous behavior only given a critical timing sequence. These new metrics can be also adapted to the validation of hardware-software systems. Experimental results show great potential of these metrics to detect design errors of their specific classes

Partial BIST insertion eliminate data correlation

A new partial BIST insertion approach based on eliminating data correlation to improve pseudo-random testability is presented. Data correlation causes the circuit to be in a subset of states more or less frequently, which leads to low fault coverage in pseudorandom test. One important cause of correlation is reconvergent fanout. Incorporating BIST test flip-flops into reconvergent paths will break correlation, however, breaking all reconvergent fanout is unnecessary since some reconvergent fanout results in negligible correlation. We introduce a metric to determine the degree of correlation caused by a set of reconvergent fanout paths. We use this metric to identify problematic reconvergent fanout which must be broken through partial BIST insertion. Based on this metric, we provide an exact method and a heuristic method to measure the data correlation. We provide an algorithm to break high correlation reconvergent paths. Our algorithm provides high fault coverage while selecting fewer BIST flip-flops than required using loop breaking techniques. Experimental results produced using our exact algorithm rank on average among the top 11.6 % of all possible solutions with the same number of flip-flops

Partial BIST Insertion to Eliminate Data Correlation

A new partial BIST insertion approach based on eliminating data correlation to improve pseudo-random testability is presented. Data correlation causes the circuit to be in a subset of the states more or less frequently, which leads to low fault coverage in pseudo-random test. One important cause of correlation is reconvergent fanout. Incorporating BIST test flip-flops into reconvergent paths will break correlation, however, breaking all reconvergent fanout is unnecessary since some reconvergent fanout result in negligible correlation. We introduce a metric to determine the degree of correlation caused by a set of reconvergent fanout paths. We use this metric to identify problematic reconvergent fanout which must be broken through partial BIST insertion. We provide an algorithm to break high correlation reconvergent paths. Our algorithm provides high fault coverage while selecting fewer BIST flip-flops than required using loop breaking techniques. Experimental results produced using our algorithm rank on average among the top 11.6% of all possible solutions with the same number of flip-flops. I

A Validation Fault Model for Timing-Induced Functional Errors

The violation of timing constraints on signals within a complex system can create timing-induced functional errors which alter the value of output signals. These errors are not detected by traditional functional validation approaches because functional validation does not consider signal timing. Timing-induced functional errors are also not detected by traditional timing analysis approaches because the errors may affect output data values without affecting output signal timing. A timing fault model, the Mis-Timed Event (MTE) fault model, is proposed to model timinginduced functional errors. The MTE fault model formulates timing errors in terms of their effects on the lifespans of the signal values associated with the fault. We use several examples to evaluate the MTE fault model. MTE fault coverage results shows that it efficiently captures an important class of errors which are not targeted by other metrics

DYNAMIC SIMULATION AND EXPERIMENTAL STUDY ON RIGID-FLEXIBLE COUPLING OF SHEARER

In order to solve the problem of large deformation of the rocker arm, the virtual prototyping technology is used to soften the front and rear rocker arm, and the dynamic and mechanical model of the shearer is established. The strain gauge data of the picking sensor are obtained, and the load data is obtained by quadratic fitting the actual calibration of the sensor and the data, and the life prediction of the key components is carried out. The results show that the stress value and the load fluctuation value of the rocker joint pin are larger when the flexible deformation of the rocker arm is considered, which indicates that the flexible deformation of the rocker arm increases the vibration impact of the whole machine and reduces the strength of the shearer And the life expectancy of the shearer’s rocker pin, the fatigue life is 1.738×10~6 times, which proves the feasibility of the experimental method and provides the theory for the selection of the rocker pin in the actual working condition