Comparison of Manual and Automatic Methods for Measurement of Methane Emission from Rice Paddy Fields

S The methane emission flux from rice paddies was simultaneously measured with automatic and manual methods in the suburban of Suzhou. Both methods were based on the static chamber/GC-FID techniques. Detail analysis of the experimental results indicates: a) The data of methane emission measured with the automatic method is reliable. b) About 11 or 19 o′clock of local time is recommended as the optimum sampling time for the manual spot measurement of methane emission from rice paddies. The methane emission fluxes measured by manual sampling at local time other than the optimum time have to be corrected. The correction coefficient may be determined by automatic and continuous measurement. c) In order to get a more accurate result, an empirical correction factor, such as 18%, is recommended to correct the seasonally total amount of measured methane emission by enlarging the automatically measured data or reducing the manually measured ones.

MODEL AND METHOD OF WELL TEST ANALYSIS FORWELLS WITH VERTICAL FRACTURE

Based on the flow mechanism of hydraulic fractured wells, through integrating linear-flow model and effective well-radius model, a new model of well test analysis for wells with vertical fracture was established. In the model, wellbore storage, the damage in the wall of fracture and all kinds of boundary conditions are considered. The model is concise in form, has intact curves and computes fast, which may meet the demand of real-time computation and fast responded well test interpretation. A new method to determine effective well radius was presented, and the correlation between effective well radius and the fracture length, fracture conductivity, skin factor of fracture was given. Matching flow rate or pressure tested, the optimization model that identified formation and fracture parameters was set up. The automatic matching method was presented by synthetically using step by step linear least square method and sequential quadratic programming. At last, the application was also discussed. Application shows that all of these results can analyze and evaluate the fracturing treatment quality scientifically and rationally, instruct and modify the design of fracturing and improve fracturing design level.

Comparison of Segmentation Algorithms for Detecting Myocardial Infarction Using Late Gadolinium Enhancement Magnetic Resonance Imaging

Objective:The aim of this study was to validate the accuracy of a new automatic method for scar segmentation and compare its performance with that of two other frequently used segmentation algorithms.Methods:Twenty-six late gadolinium enhancement cardiovascular magnetic resonance images of diseased hearts were segmented by the full width at half maximum(FWHM)method,the n standard deviations(n SD)method,and our new automatic method.The results of the three methods were compared with the consensus ground truth obtained by manual segmentation of the ventricular boundaries.Results:Our automatic method yielded the highest Dice score and the lowest volume difference compared with the consensus ground truth segmentation.The n SD method produced large variations in the Dice score and the volume difference.The FWHM method yielded the lowest Dice score and the greatest volume difference compared with the automatic,6SD,and 8SD methods,but resulted in less variation when different observers segmented the images.Conclusion:The automatic method introduced in this study is highly reproducible and objective.Because it requires no manual intervention,it may be useful for processing large datasets produced in clinical applications.

Numerical and Experimental Analysis of A Ducted Propeller Designed by A Fully Automated Optimization Process Under Open Water Condition

A fully automated optimization process is provided for the design of ducted propellers under open water conditions, including 3D geometry modeling, meshing, optimization algorithm and CFD analysis techniques. The developed process allows the direct integration of a RANSE solver in the design stage. A practical ducted propeller design case study is carried out for validation. Numerical simulations and open water tests are fulfilled and proved that the optimum ducted propeller improves hydrodynamic performance as predicted.

Automatic target recognition method for inverse synthetic aperture sonar imaging

To address the randomness of target aspect angle and the incompleteness of observed target in inverse synthetic aperture sonar（ISAS） imaging,a method for target recognition is proposed based on topology vector feature（TVF） of multiple highlights. Analysis of the projection relationship from 3 D space to 2 D imaging plane in ISAS indicates that the distance between two highlights in the cross-range scale calibrated image is determined by the distance between the corresponding physical scattering centers. Then, TVFs of different targets, which remain stable in various possibilities of target aspect angle, can be built. K-means clustering technique is used to effectively alleviate effect of the point missing due to incompleteness of the observed target. A nearest neighbor classifier is used to realize the target recognition. The ISAS experimental results using underwater scaled models are provided to demonstrate the effectiveness of the proposed method. A classification rate of 84.0% is reached.

Efcient autofocus method for sequential automatic capturing of high-magnification microscopic images

This letter presents an autofocus （AF） method to position a high-magnification microscope lens that automatically captures hundreds of images from a single moving slide. These images are taken by a mobile clinic unit in a rural location, and are later automatically processed and revised by a remote specialist. This process requires high focus precision to enable image processing techniques to achieve proper results. Low focusing times are also required for the system to be operative. We propose a novel method that combines two focus measures with an adapted searching scheme to cope with both constraints.

Automatic Modeling of Virtual Humans and Body Clothing

Highly realistic virtual human models are rapidly becoming commonplace incomputer graphics. These models, often represented by complex shape and requiring labor-intensiveprocess, challenge the problem of automatic modeling. The problem and solutions to automaticmodeling of animatable virtual humans are studied. Methods for capturing the shape of real people,parameterization techniques for modeling static shape (the variety of human body shapes) and dynamicshape (how the body shape changes as it moves) of virtual humans are classified, summarized andcompared. Finally, methods for clothed virtual humans are reviewed.

Diurnal Variation of MCSs over Asia and the Western Pacific Region

Mesoscale convective systems （MCSs） are severe disaster-producing weather systems. Radar data and infrared satellite image are useful tools in MCS surveillance. The previous method of MCS census is to look through the printed infrared imagery manually. This method is not only subjective and inaccurate, but also inefficient. Different from previous studies, a new automatic MCS identification （AMI） method, which overcomes the above disadvantages, is used in the present study. The AMI method takes three steps： searching potential MCS profiles, tracking the MCS, and assessing the MCS, so as to capture MCSs from infrared satellite images. Finally, 47468 MCSs are identified over Asia and the western Pacific region during the warm seasons （May-October） from 1995 to 2008. From this database, the geographical distribution and diurnal variation of MCSs are analyzed. The results show that different types of MCSs have similar geographical distributions. Latitude is the main control factor for MCS distribution. MCSs are most frequent over the central Tibetan Plateau; meanwhile, this area also has the highest hail frequency according to previous studies. ~rther, it is found that the diurnal variation of MCSs has little to do with MCSs＇ size or shape; MCSs in different areas have their own particular diurnal variation patterns. Based on the diurnal variation characteristics, MCSs are classified into four categories： the whole-day occurring MCSs in low latitude, the whole-day occurring MCSs in high latitude, the nocturnal MCSs, and the postmeridian MCSs. MCSs over most places of China's Mainland are postmeridian; but MCSs over the Sichuan basin and its vicinity are nocturnal. This conclusion is coincidental with the hail climatology of China.