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Smallholders are essential in ensuring food security; however, smallholder-dominated food production often involves high resource-environmental costs. This study analyzed the factors that differentiate horticultural practices, willingness to adopt technology and social networks between optimized practices (OPT) and farmer practices (FP) to provide localized and systematic solutions for the sustainable apple production.

To explore the approach of smallholder-dominated sustainable apple production, 257 apple producers in the Bohai Bay region, a major apple planting area in China, were investigated. Life cycle assessment (LCA), emergy analysis and social network analysis methods were used for evaluation.

The results showed that the net economic profit and emergy sustainability index (ESI) in OPT was 15.8 × 104 RMB·ha-1 and 1.2, respectively, which were 126.9 and 128.0% higher than FP. In contrast, greenhouse gas (GHG) emissions under OPT was 29.3% lower than those under FP. OPT has a higher percentage of adoption of scientific fertilizer application and water-saving irrigation technologies compared to FP. OPT has strong learning abilities, more social resources (such as technical training and sharing technical experience with others) and connections with stakeholders in the apple supply chain. Optimizing smallholders' social capital, willingness to adopt technology, behavioral willingness and technological awareness can promote sustainable apple production.

Considering the horticultural practices employed by smallholders in conjunction with their social networks, these factors contributed to the transition of smallholder-led apple production toward sustainability. The findings provided viable options and a theoretical basis for smallholder-dominated crop production to move toward sustainability, with significant implications for policymakers.

The purpose of this paper is to propose a method for selecting the position and attitude trajectory of error measurement to improve the kinematic calibration efficiency of a one translational and two rotational (1T2R) parallel power head and to improve the error compensation effect by improving the properties of the error identification matrix.

First, a general mapping model between the endpoint synthesis error is established and each geometric error source. Second, a model for optimizing the position and attitude trajectory of error measurement based on sensitivity analysis results is proposed, providing a basis for optimizing the error measurement trajectory of the mechanism in the working space. Finally, distance error measurement information and principal component analysis (PCA) ideas are used to construct an error identification matrix. The robustness and compensation effect of the identification algorithm were verified by simulation and through experiments.

Through sensitivity analysis, it is found that the distribution of the sensitivity coefficient of each error source in the plane of the workspace can approximately represent its distribution in the workspace, and when the end of the mechanism moves in a circle with a large nutation angle, the comprehensive influence coefficient of each sensitivity is the largest. Residual analysis shows that the robustness of the identification algorithm with the idea of PCA is improved. Through experiments, it is found that the compensation effect is improved.

A model for optimizing the position and attitude trajectory of error measurement is proposed, which can effectively improve the error measurement efficiency of the 1T2R parallel mechanism. In addition, the PCA idea is introduced. A least-squares PCA error identification algorithm that improves the robustness of the identification algorithm by improving the property of the identification matrix is proposed, and the compensation effect is improved. This method has been verified by experiments on 1T2R parallel mechanism and can be extended to other similar parallel mechanisms.

The ever-increasing demand and consumption of energy and the effects of global warming with its long-term comrade, climate change, is obvious today than ever before. In today’s world, naturally-ventilated buildings hardly provide the satisfaction that occupants need and wish for. It’s on this backdrop that the study aims to investigate how responsive buildings on the Kwame Nkrumah University of Science and Technology, Kumasi, Ghana campus are to its warm humid climate and assess students thermal comfort levels.

Quantitative approach was adopted for the study. Empirical investigation was carried out using the survey approach. In total, 14 buildings (offices, classrooms and halls of residences) were assessed using the Mahoney Tables. Again, subjective thermal perceptions of occupants in the halls of residences was sought. A total of 214 valid questionnaires were used for the analysis.

Adaptive principles like the Mahoney Tables are not followed in recent years. Even where these principles have been followed, indoor spaces were still found to be uncomfortable. In total, 58 per cent of the occupants in all the three halls of residence voted in the comfort band: an indication unacceptable sensations. Warm sensation votes (44 per cent) was more than cool sensation votes (29 per cent). In warm sensation, 39 per cent of the subjects preferred cooler environment. The occupants felt that opening windows and the use of fans could keep them comfortable. Moreover, 48 per cent of the subjects voted that their fans and windows were effective.

The papers contribution to the body of knowledge is the provision of empirical evidence in the field of adaptive designs and thermal comfort. There is a strong indication from the results that human activities in terms of blatant disregard for laid down design principles coupled with the worsening situation of global warming is making interior spaces ever uncomfortable.