Design and Implementation of Container Positioning System Based on Wireless Sensor Network

This paper aims to create an efficient container yard management system. For this purpose, a gantry crane management subsystem was designed and implemented for container information management based on the wireless sensor network (WSN). The system consists of a set of desktop management software and three different types sensor nodes, and locates the container via the two-way symmetrical time-of-arrival (TS-TOA) positioning approach. In this way, the subsystem enhances the accuracy of container positioning without elevating hardware cost. Through the implementation of the hardware and software systems, it is proved that the user can successfully locate the container, read and update cargo information, and complete similar operations through human-computer interaction in the desktop management software. Overall, this research greatly improves the efficiency of container management at the port, and helps to reduce the operational cost and port congestion.</span

Are medical record front page data suitable for risk adjustment in hospital performance measurement? Development and validation of a risk model of in-hospital mortality after acute myocardial infarction

Objectives To develop a model of in-hospital mortality using medical record front page (MRFP) data and assess its validity in case-mix standardisation by comparison with a model developed using the complete medical record data.Design A nationally representative retrospective study.Setting Representative hospitals in China, covering 161 hospitals in modelling cohort and 156 hospitals in validation cohort.Participants Representative patients admitted for acute myocardial infarction. 8370 patients in modelling cohort and 9704 patients in validation cohort.Primary outcome measures In-hospital mortality, which was defined explicitly as death that occurred during hospitalisation, and the hospital-level risk standardised mortality rate (RSMR).Results A total of 14 variables were included in the model predicting in-hospital mortality based on MRFP data, with the area under receiver operating characteristic curve of 0.78 among modelling cohort and 0.79 among validation cohort. The median of absolute difference between the hospital RSMR predicted by hierarchical generalised linear models established based on MRFP data and complete medical record data, which was built as ‘reference model’, was 0.08% (10th and 90th percentiles: −1.8% and 1.6%). In the regression model comparing the RSMR between two models, the slope and intercept of the regression equation is 0.90 and 0.007 in modelling cohort, while 0.85 and 0.010 in validation cohort, which indicated that the evaluation capability from two models were very similar.Conclusions The models based on MRFP data showed good discrimination and calibration capability, as well as similar risk prediction effect in comparison with the model based on complete medical record data, which proved that MRFP data could be suitable for risk adjustment in hospital performance measurement