ABSTRACT The accurate acquisition of crop planting area information allows for agricultural management departments to understand crop production information promptly. Concurrently, support vector machine (SVM) algorithms are unable to determine parameter combinations in remote sensing image crop classification to obtain optimal classification results. To solve this issue, this paper proposes an SVM that is optimized by the adaptive mutation particle swarm optimization algorithm. To test the algorithm, we undertook an experiment in Acheng District, Harbin City, Heilongjiang province, China, using Gaofen 1/wide-field-view satellite images to construct a time series for various vegetation indices. The SVM model with optimized parameters was compared with a traditional backpropagation neural network, a decision tree, and an SVM without parameter optimization. The experimental results verified that the improved SVM model obtained the highest classification accuracy.

ABSTRACT This study used a spectral index method and an artificial intelligence algorithm to quantitatively analyze rice canopy soil and plant analyzer development (SPAD) based on ground nonimaging spectral data and UAV hyperspectral images to build a high-precision SPAD prediction model for nondestructive monitoring of the chlorophyll relative content of rice in cold regions. First, this study First, this study selected characteristic bands sensitive to SPAD using uninformative variable elimination and the successive projections algorithm. Then, the correlation between commonly used vegetation indices and SPAD was analyzed. Finally, this study constructed a back propagation neural network (BPNN) model, BPNN with particle swarm optimization (PSO-BPNN) model, and BPNN with genetic algorithm optimization (GA-BPNN) model, and then verified the reliability of these models. According to the results, GA-BPNN had the best predictive effect. The coefficient of the determination reached 0.818, and the root mean square error was 0.847. GA-BPNN model combined with UAV hyperspectral images were used for inversion mapping; the predicted range of SPAD was 33.1–41.2, which is in good agreement with the measured value (32.7–40.6). The inversion of regional rice canopy SPAD by nonimaging spectral data and UAV hyperspectral images had high credibility, which provided technical support for the scientific management of rice in a cold region.

Resumo Fundamento O ácido úrico (AU), produto final do metabolismo dos nucleotídeos das purinas, participa dos processos de doenças metabólicas e cardiovasculares. Evidências experimentais sugerem que o ácido úrico é um mediador importante na resposta fisiológica ao aumento da pressão arterial. Objetivo Avaliar a associação entre os níveis séricos de AU e pré-hipertensão e hipertensão em uma população chinesa. Métodos Conduziu-se um estudo transversal entre março e setembro de 2017, e 1.138 participantes com idades entre 35 e 75 anos foram incluídos neste estudo, onde 223 normotensos, 316 pré-hipertensos e 599 hipertensos foram selecionados para avaliar a associação entre níveis séricos de AU e hipertensão. Considerou-se um valor de p<0,05 estatisticamente significativo. Resultados Os níveis séricos de AU foram significativamente maiores no grupo pré-hipertensão e hipertensão em comparação com o grupo controle em toda a população (p<0,05 para todos). A análise quantitativa das características indicou níveis séricos de AU (2,92±0,81, 3,06±0,85, 3,22±0,98 mg/d) linearmente aumentados em mulheres normotensas, pré-hipertensas e hipertensas, com um valor de p de 0,008. Os níveis séricos de AU nos quartis correlacionaram-se positivamente com a PAD (p<0,05), principalmente em mulheres. Após o ajuste para idade, sexo, índice de massa corporal (IMC), glicose (GLI), colesterol total (CT), triglicerídeos (TG), colesterol HDL (lipoproteína de alta densidade), as razões de chances ( odds ratios — ORs) e intervalos de confiança (IC) de 95% da pré-hipertensão, dos níveis séricos de AU mais baixos (referentes) aos mais altos foram 1,718 (1,028–2,872), 1,018 (0,627–1,654) e 1,738 (1,003–3,010). Além disso, o segundo quartil dos níveis séricos de AU esteve significativamente associado à hipertensão, com uma OR (IC 95%) de 2,036 (1,256–3,298). Conclusões O presente estudo sugere que níveis séricos mais elevados de AU estão positivamente associados à pré-hipertensão e hipertensão entre adultos chineses.

Abstract Background Uric acid (UA), the end product of purine nucleotide metabolism, participates in the processes of metabolic and cardiovascular diseases. Experimental evidence suggests it is an important mediator in the physiological response to blood pressure increase. Objective To evaluate the association between serum UA levels and pre-hypertension and hypertension in a Chinese population. Methods A cross-sectional study was conducted from March to September 2017, and 1,138 participants aged 35 to 75 were enrolled in this study, where 223 normotensive, 316 pre-hypertensive, and 599 hypertensive subjects were selected to evaluate the association between serum UA levels and hypertension. A p-value <0.05 was considered statistically significant. Results Serum UA levels were significantly higher in the pre-hypertension and hypertension group compared to the control group in the entire population (p<0.05 for all). Quantitative trait analysis indicated that serum UA levels were (2.92±0.81, 3.06±0.85, 3.22±0.98 mg/d) linearly increased in normotensive, pre-hypertensive and hypertensive females, with a p value of 0.008. Serum UA levels in the quartiles were positively correlated with DBP (p<0.05), particularly in females. After adjusting for age, gender, body mass index (BMI), glucose (GLU), total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-c), the odds ratios (ORs) and 95% confidence intervals (CIs) of pre-hypertension from the lowest (referent) to the highest levels of serum UA were 1.718 (1.028–2.872), 1.018 (0.627–1.654) and 1.738 (1.003–3.010). Additionally, the second quartile of serum UA levels were significantly associated with hypertension, with an OR (95% CI) of 2.036 (1.256–3.298). Conclusions This study suggests that higher serum UA levels are positively associated with pre-hypertension and hypertension among Chinese adults.

Abstract: As a key marketing tool, online sales promotion has been widely used by online retailers to increase sales of products and brands. Most previous researches on online sales promotion have ignored the effect of consumers’ psychological factors and the heterogeneity of product and consumers. The purpose of this study is to examine the role of psychological distance and involvement on consumers’ buying behavior in large online promotion activities. The research model was examined using empirical analysis of data obtained from consumer surveys after the Double 11 promotion. Our results indicate that temporal distance has positive impact on purchase decision of high involvement products, while having negative impact on purchase decision of low involvement products. Social distance has negative impact on consumers’ purchase decision. Temporal distance is positively associated with consumers’ purchase-decision involvement, and then purchase-decision involvement positively impacts consumers’ total consumption. Social distance has no impact on consumers’ purchase decision involvement. These findings not only advance the understanding of the role of psychological distance and involvement in online sales promotion but also offer implications regarding strategies that online retailers can employ to publish their promotions at different times and encourage consumers more to share promotional information among their friends.