Fault Diagnosis and Separation for a Distributed Rotary-laser Scanning System

The wMPS is a laser-based measurement system used for large scale metrology.However,it is susceptible to external factors such as vibrations,which can lead to unreliable measurements.This paper presents a fault diagnosis and separation method which can counter this problem.To begin with,the paper uses simple models to explain the fault diagnosis and separation methods.These methods are then mathematically derived using statistical analysis and the principles of the wMPS.A comprehensive solution for fault diagnosis and separation is proposed,considering the characteristics of the wMPS.The effectiveness of this solution is verified through experimental observations.It can be concluded that this approach can detect and separate false observations,thereby enhancing the reliability of the wMPS.

Comparison of TMI and AMSR-E sea surface temperatures with Argo near-surface temperatures over the global oceans

Satellite-derived sea surface temperatures（SSTs） from the tropical rainfall measuring mission（TRMM）microwave imager（TMI） and the advanced microwave scanning radiometer for the earth observing system（AMSR-E） were compared with non-pumped near-surface temperatures（NSTs） obtained from Argo profiling floats over the global oceans. Factors that might cause temperature differences were examined, including wind speed, columnar water vapor, liquid cloud water, and geographic location. The results show that both TMI and AMSR-E SSTs are highly correlated with the Argo NSTs; however, at low wind speeds, they are on average warmer than the Argo NSTs. The TMI performs slightly better than the AMSR-E at low wind speeds, whereas the TMI SST retrievals might be poorly calibrated at high wind speeds. The temperature differences indicate a warm bias of the TMI/AMSR-E when columnar water vapor is low, which can indicate that neither TMI nor AMSR-E SSTs are well calibrated at high latitudes. The SST in the Kuroshio Extension region has higher variability than in the Kuroshio region. The variability of the temperature difference between the satellite-retrieved SSTs and the Argo NSTs is lower in the Kuroshio Extension during spring. At low wind speeds, neither TMI nor AMSR-E SSTs are well calibrated, although the TMI performs better than the AMSR-E.

Diameters and form of skull base foramen ovale measured by three-dimensional spiral CT thin-slice scan in healthy adults

BACKGROUND： The accurate measurements of various data of the bone diameters of foramen ovale of living person can change the methods of puncturing trigeminal gasserian ganglion via foramen ovale for treating trifacial neuralgia from the experience of puncture operator only to puncture by taking the objective data of measurement as the evidence, which is good for improving the accuracy of puncturing trigeminal ganglion and reducing side effects. OBJECTIVE ： To observe the forms of foramen ovales in healthy adults displayed by volume rendering and multi-planar reconstruction after three-dimensional spiral CT thin-slice scan of skull base, and measure the longitudinal diameter and transverse diameter. DESIGN ： A repetitive observation and measurement SETTINGS ： Department of Neurosurgery and Department of Medical Imaging, Foshan Hospital of Traditional Chinese Medicine. PARTICIPANTS： Fifty healthy adults （100 sides）, who were examined with three-dimensional spiral CT scan, were randomly selected from the Department of Medical Imaging, Foshan Hospital of Traditional Chinese Medicine from January 2005 to January 2006, including 26 males and 24 females, aged 25-68 years with an average of 48 years old. They were all informed and agreed with the examination. METHODS ： The subjects were examined with the Philips 16-slice spiral CT-Mx 8000 IDT CT apparatus （Philips Company, Holland）, the scanning ranged from 2 cm below the canthomeatal line to the level of suprasellar cistem. The width of collimator was 0.75 mm, pitch was 0.663; tube current was 350 mA, voltage was 120 kV, resolution was 512×512 matrix; slice thickness of reconstruction was 1 mm, and interval was 0.5 mm. After the three-dimensional spiral CT thin-slice scan of skull base, the image post-processing techniques including volume rendering and multi-planar reconstruction were applied to observe the forms of foramen ovales, and measure the size, longitudinal diameter and transverse diameter of the foramen ovales. The figures of the foramen ovales were drawn with mouse along the boundary of bone porous margin and soft tissue. According to the indications, the diameters were measured with computer to observe the forms of foramen ovales. MAIN OUTCOME MEASURES ： The longitudinal diameter, transverse diameter and form of foramen ovales were observed. RESULTS： All the 50 healthy adults （100 sides） were involved in the analysis of results. （1） It was observed in the volume rendering images that foramen ovales had four forms of oval shape （77 sides）, kidney shape （12 sides）, round shape （7 sides）, ribbon shape （4 sides）. （2） The longitudinal diameters of left and right foramen ovales were （7.67±1.32） and （7.98±1.45） mm, and the transverse diameters were （4.04±0.83）, （4.09±1.07） mm; There was no obvious difference between left and right longitudinal diameters （t = 1.63, P = 0.11 ）, and left and right transverse diameters were close （t = 0.45, P= 0.65）. CONCLUSION ： The non-invasive techniques of volume rendering and multi-planar reconstruction after three-dimensional spiral CT thin-slice scan can clearly display the formand size of foramen ovale in healthy adults.

Galvanic Corrosion Behavior of Copper-Drawn Steel for Grounding Grids in the Acidic Red Soil Simulated Solution

The influence of pH and metallographic structure on the corrosion behavior of copper-drawn steel is studied with the simulated system.The effect of pH on the corrosion behavior of copper-drawn steel has been investigated using open-circuit potential,potentiodynamic polarization,galvanic current measurement,scanning electron microscopy and scanning vibrating electrode technique techniques.The steel is corroded as anode,while the corrosion of copper plate is protected as cathode.All the results revealed that pH and metallographic structure had a significant influence on the corrosion behavior of copper-drawn steel.With the decrease in pH value from 6 to 2.4,the corrosion rate of copper-drawn steel galvanic couple(Cu-Fe GC)obviously increased in the simulated solution of acidic red soil.The electric field formed by the Cu-Fe GC changes the direction of ion migration between the copper and drawn steel electrodes,which impacts the composition and microstructure of corrosion products formed on the electrode surface.