Building embedded quasi-time-optimal controller for two-wheeled self-balancing robot

In this paper, two-wheeled self-balancing robot problem is introduced, and a quasi-time-optimal approach is applied to synthesize the control law. The result is compared with that of other methods. The process for designing and building the testting model, implementing the synthesized control law is also described

Trends in rice-based farming systems in the Mekong Delta

Rice-based farming systems in the Mekong Delta have been transformed over the last four decades. Needing to boost rice production after 1975, the government increased investment in water control and irrigation and promoted intensification of rice farming through green revolution technology, leading to widespread adoption of double- and triple-cropping systems. As a result, the area of rice increased from 2.0 million ha in the late 1970s to 4.3 million ha in 2016. The yield of the wet-season crop increased from 2 t/ha in 1975 to 5.3 t/ha in 2016. Total paddy production increased from 4 million t in 1975 to 24.2 million t in 2016, the increase attributable equally to the increase in area and the increase in yields. From being a net importer of rice in the 1970s and 1980s, Vietnam exported 4.5 million t worth USD 2 billion in 2016, 90% of which was produced in the Delta. However, the focus on rice intensification has shifted since 2000 as the impacts on farmer livelihoods and the environment have become apparent. Locking farmers into producing low-quality rice for export has not provided adequate returns, especially as demand has shifted in favour of higher-quality rice and more diverse diets. Intensive use of fertilisers and pesticides has led to soil and water pollution and reduction in wild food supply. Moreover, the “total management” of hydrology in the Delta has had major impacts on water flows, sedimentation processes, aquatic species, and land-use options. In response, the government has progressively relaxed its restrictions on the use of paddy lands and rice-based farming systems have become more diversified, with the increased use of paddy lands for non-rice field crops, orchards, and freshwater and brackish-water aquaculture. The current policy promotes high-quality rice, reduced rice area, further diversification of farming systems, and promotion of agro-ecological and organic agriculture