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The water depth bias of LiDAR point cloud data has to be corrected. The previous models, which used the fixed parameters for an entire water area, cannot efficiently correct the bias due to the different water environments. Therefore, this paper develops an adaptive model for the correction of the water depth bias. A coordinate system, in which the water depth is taken as the X-axis and the water depth bias is taken as the Y-axis, is defined. All of the sample points are normalized, and then projected into the defined coordinate system according to their water depths and water depth biases. Second, the scatter points are clustered into several different clusters using the developed subdivision algorithm. With the clusters, an entire water area is subdivided into several sub-regions. Finally, each sub-region is fitted using a model, which is used to correct the water depth bias. Experimental verification and comparison analysis are conducted in three different environments: an indoor tank, an outdoor pond and the Beihai sea. The experimental results demonstrate that the Mean Absolute Error (MAE) and the Root Mean Squared Error (RMSE) from the adaptive model are reduced by approximately 61% and 59%, respectively, relative to those from the traditional models. Therefore, it can be concluded that the proposed model can adapt to changes of the different water environments and achieve a higher accuracy for water depth bias correction than traditional methods do.

Introduction: In the post-pandemic period of COVID-19, the majority of cities in China try to balance the normalization of epidemic prevention and social-economic development. However, the appearance of asymptomatic infected patients poses threats to public health, which might be infectious without clinical symptoms and only be detected by testing approaches. Methods: Along with the appearance of one symptomatic case, a regional large-scale screening program was carried out in Shenzhen City charged by a regionally integrated healthcare system. After describing the screening program, a retrospective cross-sectional study for the screening outcome and efficacy was conducted. Discussion: According to the screening results, the asymptomatic case was infectious and their close contacts should be quarantined cautiously as the close contacts of symptomatic cases. Besides, after integrating medical resources in Luohu district of Shenzhen, the medical capability of Luohu district improved greatly which could be demonstrated in inspection and organization abilities in this screening program. Conclusion: The large-scale screening contributed to preventing epidemic transmission. In the post-pandemic period, regular surveillance of asymptomatic cases and rapid response capability for emergent screening program are both crucial for the prevention and control of COVID-19 epidemic. The integrated healthcare system coordinating regional medical institutions and optimizing regional medical recourse has advantages to address public health emergencies.

Objective: To evaluate the impact of the integrated care in Luohu, China on the hypertension management. Methods: Hypertensive patients aged 35–74 years were recruited by the cluster-randomized sampling method from Luohu district which adopted integrated care and another district that remained original routine care during October 2018~January 2020, with 1353 and 583 patients from integrated and routine care communities, respectively. Health information, knowledge, attitude, and practice (KAP) towards cardiovascular diseases, pharmaceutical expenditure on hypertension and its comorbidities, and healthcare-related satisfaction were collected by questionnaires, with the expenditure additionally verified by hospitals’ billing records database. Continuous and categorical variables were compared by Wilcoxon test and Chi-square test, respectively. The age-standardized hypertension control rate was calculated by direct standardization. Results: The standardized hypertension management rate in the integrated care communities (45.75%) was significantly higher than that in routine care communities (14.07%) (P < 0.0001), while the age-standardized hypertension control rates were similar (integrated care: 50.3%, routine care: 52.65%, P = 0.518). The pharmaceutical expenditure on hypertension and its comorbidities in the integrated care communities was Ұ264.23 ± 357.38/month/person, lower than that in the routine care communities (Ұ354.56 ± 430.59/month/person). Patients in the integrated care had higher KAP scores (73.48 ± 11.54), compared with routine care (68.89 ± 15.51) (P < 0.0001). Moreover, the integrated care communities had higher satisfaction rates towards the convenience of dual referral (90.15% vs. 77.99%) and service quality (95.18% vs. 87.81%) than routine care communities (P < 0.0001). Conclusion: The practice of the integrated care in Luohu has substantially improved the hypertension management and the healthcare-related satisfaction while with relatively low pharmaceutical expenditure. The investigation of long-term impact of the integrated care on hypertension control and management is warranted.

Traditional bathymetry LiDAR (light detection and ranging) onboard manned and/or unmanned airborne systems cannot operate in the context of narrow rivers in urban areas with high buildings and in mountainous areas with high peaks. Therefore, this study presents a prototype of a lightweight bathymetry LiDAR onboard an unmanned shipborne vehicle (called “GQ-Cor 19”). The GQ-Cor 19 system primarily includes an emitting optical module, a receiving optical module, control module, detection module, high-speed A/D sampling module, and data processing system. Considering that the “GQ-Cor 19” is extremely close to the water surface, various new technical challenges are encountered, such as significant laser scattering energy from the surface of the water, which saturates signals received by the photomultiplier tube detector. Therefore, this study presents various new technical solutions, including (1) an improved Bresenham algorithm, (2) a small and lightweight receiving optical system with a split-field method, and (3) a data acquisition module with a high-speech A/D collector. Following a series of different experimental verifications, the results demonstrate that the new generation of single-band LiDAR onboard an unmanned shipborne vehicle can swiftly measure the underwater depth, and the maximum measurement depth is more than 25 m. The measurement accuracy is better than 30 cm and the weight is less than 12 kg.