New calibration method using low cost MEM IMUs to verify the performance of UAV-borne MMS payloads.

Spatial information plays a critical role in remote sensing and mapping applications such as environment surveying and disaster monitoring. An Unmanned Aerial Vehicle (UAV)-borne mobile mapping system (MMS) can accomplish rapid spatial information acquisition under limited sky conditions with better mobility and flexibility than other means. This study proposes a long endurance Direct Geo-referencing (DG)-based fixed-wing UAV photogrammetric platform and two DG modules that each use different commercial Micro-Electro Mechanical Systems' (MEMS) tactical grade Inertial Measurement Units (IMUs). Furthermore, this study develops a novel kinematic calibration method which includes lever arms, boresight angles and camera shutter delay to improve positioning accuracy. The new calibration method is then compared with the traditional calibration approach. The results show that the accuracy of the DG can be significantly improved by flying at a lower altitude using the new higher specification hardware. The new proposed method improves the accuracy of DG by about 20%. The preliminary results show that two-dimensional (2D) horizontal DG positioning accuracy is around 5.8 m at a flight height of 300 m using the newly designed tactical grade integrated Positioning and Orientation System (POS). The positioning accuracy in three-dimensions (3D) is less than 8 m.

Proteome demonstration of alpha-1-acid glycoprotein and alpha-1-antichymotrypsin candidate biomarkers for diagnosis of enterovirus 71 infection.

BACKGROUND: Human enterovirus 71 (EV71) is the major causative agents of hand-foot-and-mouth disease and frequently associated with severe complications such as encephalitis and death. Understanding the host response following enteroviral infection may facilitate the development of biomarkers for EV71 infections. METHODS: We implemented two-dimensional gel electrophoresis technology on proteins prepared from serum obtained from 4 mild and 4 severe cases of EV71 infections and 4 healthy control children, to investigate the differentially expressed proteins. The differential expressed proteins were further identified with liquid chromatography-mass spectrometry/mass spectrometry analysis and western blotting validation. RESULTS: A total of 27 differentially expressed proteins were picked and identified with liquid chromatography-mass spectrometry/mass spectrometry. Of the 27 identified proteins, 6 proteins were up-regulated in the mild-infected and severe EV71-infected patients in comparison to the healthy control group. Two proteins, alpha-1-acid-glycoprotein (AGP1) and alpha-antichymotrypsin (AACT), were not detected in the EV71-infected patients, but appeared in the control patient. Western blotting analysis demonstrated that AGP1 and AACT proteins were negatively associated with the clinical severity of EV71 infection. Similarly, both of the proteins were not detected in the secretion medium from the EV71-infected neuroblastoma cells, but detected in the mock-infected cells, suggesting that differentially expressed AGP1/AACT protein levels are in response to EV71 infections. CONCLUSIONS: Two candidate proteins AGP1 and AACT, whose expression levels were reduced under the EV71 infection pathological condition, provide useful source of information for potential diagnostic biomarkers of EV71 infection in children.

The development of an UAV borne direct georeferenced photogrammetric platform for Ground Control Point free applications.

To facilitate applications such as environment detection or disaster monitoring, the development of rapid low cost systems for collecting near real time spatial information is very critical. Rapid spatial information collection has become an emerging trend for remote sensing and mapping applications. In this study, a fixed-wing Unmanned Aerial Vehicle (UAV)-based spatial information acquisition platform that can operate in Ground Control Point (GCP) free environments is developed and evaluated. The proposed UAV based photogrammetric platform has a Direct Georeferencing (DG) module that includes a low cost Micro Electro Mechanical Systems (MEMS) Inertial Navigation System (INS)/Global Positioning System (GPS) integrated system. The DG module is able to provide GPS single frequency carrier phase measurements for differential processing to obtain sufficient positioning accuracy. All necessary calibration procedures are implemented. Ultimately, a flight test is performed to verify the positioning accuracy in DG mode without using GCPs. The preliminary results of positioning accuracy in DG mode illustrate that horizontal positioning accuracies in the x and y axes are around 5 m at 300 m flight height above the ground. The positioning accuracy of the z axis is below 10 m. Therefore, the proposed platform is relatively safe and inexpensive for collecting critical spatial information for urgent response such as disaster relief and assessment applications where GCPs are not available.

Well-chosen method for an optimal design of doublet lens design.

This paper presents a method for choosing a doublet design for the correction of longitudinal chromatic, spherical and coma aberrations. A secondary dispersion formula is utilized to sort out minimal longitudinal chromatic aberrations for the doublet. The program is developed with the Matlab software. An optimal doublet design to efficiently reduce both spherical aberration and coma will incorporate glass combination with a sufficiently large difference in the V-numbers and small powers. We succeed in obtaining an optimal doublet design with the proposed method.