Indoor Human Fall Detection Algorithm Based on Wireless Sensing

As the main health threat to the elderly living alone and performing indoor activities, falls have attracted great attention from institutions and society. Currently, fall detection systems are mainly based on wear sensors, environmental sensors, and computer vision, which need to be worn or require complex equipment construction. However, they have limitations and will interfere with the daily life of the elderly. On the basis of the indoor propagation theory of wireless signals, this paper proposes a conceptual verification module using Wi-Fi signals to identify human fall behavior. The module can detect falls without invading privacy and affecting human comfort and has the advantages of noninvasive, robustness, universality, and low price. The module combines digital signal processing technology and machine learning technology. This paper analyzes and processes the channel state information (CSI) data of wireless signals, and the local outlier factor algorithm is used to find the abnormal CSI sequence. The support vector machine and extreme gradient boosting algorithms are used for classification, recognition, and comparative research. Experimental results show that the average accuracy of fall detection based on wireless sensing is more than 90%. This work has important social significance in ensuring the safety of the elderly.Temple University. College of Science and TechnologyComputer and Information Science

Genetic Diversity and Linkage Disequilibrium in Chinese Bread Wheat (Triticum aestivum L.) Revealed by SSR Markers

Two hundred and fifty bread wheat lines, mainly Chinese mini core accessions, were assayed for polymorphism and linkage disequilibrium (LD) based on 512 whole-genome microsatellite loci representing a mean marker density of 5.1 cM. A total of 6,724 alleles ranging from 1 to 49 per locus were identified in all collections. The mean PIC value was 0.650, ranging from 0 to 0.965. Population structure and principal coordinate analysis revealed that landraces and modern varieties were two relatively independent genetic sub-groups. Landraces had a higher allelic diversity than modern varieties with respect to both genomes and chromosomes in terms of total number of alleles and allelic richness. 3,833 (57.0%) and 2,788 (41.5%) rare alleles with frequencies of <5% were found in the landrace and modern variety gene pools, respectively, indicating greater numbers of rare variants, or likely new alleles, in landraces. Analysis of molecular variance (AMOVA) showed that A genome had the largest genetic differentiation and D genome the lowest. In contrast to genetic diversity, modern varieties displayed a wider average LD decay across the whole genome for locus pairs with r2>0.05 (P<0.001) than the landraces. Mean LD decay distance for the landraces at the whole genome level was <5 cM, while a higher LD decay distance of 5–10 cM in modern varieties. LD decay distances were also somewhat different for each of the 21 chromosomes, being higher for most of the chromosomes in modern varieties (<5∼25 cM) compared to landraces (<5∼15 cM), presumably indicating the influences of domestication and breeding. This study facilitates predicting the marker density required to effectively associate genotypes with traits in Chinese wheat genetic resources

Preparation and Consolidation Mechanism of Nickel Laterite Carbon Composite Hot Briquette

Abstract Blast furnace smelting process has advantages in producing ferronickel products because of its low comprehensive energy consumption and high production efficiency. However, laterite nickel ore has poor performance of pellets and lump ore due to its own characteristics. At present, the main lumping method is low basicity sinter, which is difficult to optimize the charge structure. This paper mainly studies the preparation process of laterite nickel carbon composite hot briquette (LN-CCHB) and the influence of process parameters on the basic compressive strength properties, so as to explore a new charge for smelting laterite nickel in blast furnace process. Results showed that the influence of pressure and temperature of hot briquette on the compressive strength of NL-CCHB is obvious. The compressive strength of NL-CCHB increases with the increase of briquetting pressure increases first and then decreases with the increase of hot briquetting temperature. The FC/O ratio (the ratio of the fixed carbon mol (C) in coal to the reducible oxygen mol (O) in iron oxides) has little effect on the compressive strength of NL-CCHB. In the experimental range, the mixture of laterite nickel ore and pulverized coal can obtain NL-CCHB with compressive strength of more than 1300N after hot briquetting. After heat treatment, NL-CCHB with compressive strength of more than 1800N can be obtained. The optimum hot briquetting process parameters are: FC/O ratio 1.25, hot briquetting temperature 450°C, hot briquetting pressure 80MPa. The optimum heat treatment process parameters are: FC/O ratio 1.50, heat treatment temperature 550°C.</jats:p

Mobility of Cellulose Nanocrystals in Porous Media: Effects of Ionic Strength, Iron Oxides, and Soil Colloids

Understanding the dispersivity and migration of cellulose nanocrystals (CNCs) in porous media is important for exploring their potential for soil and water remediation. In this study, a series of saturated column experiments were conducted to investigate the coupled effects of ionic strength, iron oxides (hematite), and soil colloids on the transport of CNCs through quartz sand and natural soils (red earth and brown earth). Results showed that CNCs had high mobility in oxide-free sand and that iron oxide coating reduced the mobility of CNCs. An analysis of Derjaguin-Landau-Verwey-Overbeek interactions indicated that CNCs exhibited a deep primary minimum, nonexistent maximum repulsion and secondary minimum on hematite-coated sand, favorable for the attachment of CNCs. The maximum effluent percentage of CNCs was 96% in natural soils at 5 mM, but this value decreased to 4% at 50 mM. Soil colloids facilitated the transport of CNCs in brown earth with larger effect at higher ionic strength. The ionic strength effect was larger in natural soils than sand and in red earth than brown earth. The study showed that CNCs can travel 0.2 m to 72 m in porous media, depending on soil properties, solution chemistry, and soil colloids.</jats:p

Interaction of Climate Change and Anthropogenic Activity on the Spatiotemporal Changes of Surface Water Area in Horqin Sandy Land, China

Surface water dynamics are sensitive to climate change and anthropogenic activity, and they exert important feedback to the above two processes. However, it is unclear how climate and human activity affect surface water variation, especially in semi-arid regions, such as Horqin Sandy Land (HQSL), a typical part of the fragile region for intensive interaction of climate and land use change in northern China. We investigated the changes of spatiotemporal distribution and the influence of climatic and anthropogenic factors on Surface Water Area (SWA) in HQSL. There are 5933 Landsat images used in this research, which were processed on the Google Earth Engine cloud platform to extract water bodies by vegetation index and water index method. The results revealed that the area and number of water bodies showed a significant decrease in HQSL from 1985 to 2020. Spatially, the SWA experienced different amplitudes of variation in the Animal Husbandry Dominated Region (AHDR) and in the Agriculture Dominated Region (ADR) during two periods; many water bodies even dried up and disappeared in HQSL. Hierarchical partitioning analysis showed that the SWA of both regions was primarily influenced by climatic factors during the pre-change period (1985–2000; the mutation occurred in 2000), and human activity has become more and more significantly important during the post-change period (2001–2020). Thus, it is predictable that SWA variation in the following decades will be influenced by the interaction of climate change and human activity, even more by the later in HQSL, and the social sectors have to improve their ability to adapt to climate change by modifying land use strategy and techniques toward the sustainable development of water resources

Conservatively transmitted alleles of key agronomic genes provide insights into the genetic basis of founder parents in bread wheat (Triticum aestivum L.)

Abstract Background Founder parents play extremely important roles in wheat breeding. Studies into the genetic basis of founder parents and the transmission rules of favorable alleles are of great significance in improving agronomically important traits in wheat. Results Here, a total of 366 founder parents, widely grown cultivars, and derivatives of four representative founder parents were genotyped based on efficient kompetitive allele-specific PCR (KASP) markers in 87 agronomically important genes controlling yield, quality, adaptability, and stress resistance. Genetic composition analysis of founder parents and widely grown cultivars showed a consistently high frequency of favorable alleles for yield-related genes. This analysis further showed that other alleles favorable for resistance, strong gluten, dwarf size, and early heading date were also subject to selective pressure over time. By comparing the transmission of alleles from four representative founder parents to their derivatives during different breeding periods, it was found that the genetic composition of the representative founder parents was optimized as breeding progressed over time, with the number and types of favorable alleles carried gradually increasing and becoming enriched. There are still a large number of favorable alleles in wheat founder parents that have not been fully utilized in breeding selection. Eighty-seven agronomically important genes were used to construct an enrichment map that shows favorable alleles of four founder parents, providing an important theoretical foundation for future identification of candidate wheat founder parents. Conclusions These results reveal the genetic basis of founder parents and allele transmission for 87 agronomically important genes and shed light on breeding strategies for the next generation of elite founder parents in wheat. </jats:sec

Additional file 23 of Conservatively transmitted alleles of key agronomic genes provide insights into the genetic basis of founder parents in bread wheat (Triticum aestivum L.)

Additional file 23: Figure S13. Allele transmission from founder parent St2422/464 to its derivatives. The favorable and alternative alleles are shown in purple and orange, respectively. Heterozygous types are shown in magenta and missing types are shown in black. Conservatively transmitted alleles are labeled at the bottom of the figure, and red font indicates that the favorable allele was conservatively transmitted

Additional file 8 of Conservatively transmitted alleles of key agronomic genes provide insights into the genetic basis of founder parents in bread wheat (Triticum aestivum L.)

Additional file 8: Table S8. Common favorable alleles, uncommon favorable alleles, and specific favorable alleles carried by four founder parents in 87 agronomically important genes