In this paper, we obtained three dimensional digital cores using X-ray CT to describe the rock microstructure and applied the open morphology algorithm to simulate oil and formation water distribution in the pore spac...In this paper, we obtained three dimensional digital cores using X-ray CT to describe the rock microstructure and applied the open morphology algorithm to simulate oil and formation water distribution in the pore space at different water saturations during the oil-displacing water flood process. The resistivity, formation factor, and resistivity index of rocks were calculated using the finite element method （FEM） and we studied the effect of rock wettability on electrical properties. The numerical simulation results indicate that the simulated formation factor and resistivity index of the water wet rock agrees well with experiments over the whole range of water saturation and extends the traditional resistivity experiment. The rock wettablilty has a large influence on the rock resistivity index. The resistivity and saturation exponent of oil wet rock are obviously larger than three of water wet rock.展开更多
A new model based on dyadic differential wavelet was developed for detecting the R peak in Holter ECG signal according to the design of data mining. The Mallat recursive filter algorithm was introduced to calculate wa...A new model based on dyadic differential wavelet was developed for detecting the R peak in Holter ECG signal according to the design of data mining. The Mallat recursive filter algorithm was introduced to calculate wavelet and optimize the detection algorithm which is based on the equivalent filter technique. The detection algorithm has been verified by MIT arrhythmia database with a high efficiency of 99%. After optimization, the algorithm was put into clinical experiment and tested in the Air Force Hospital in Tianjin for about two months. After about 108 hearts beating test of more than 100 patients, the total efficient detection rate has reached 97%. Now this algorithm module has been applied in business software and shows perfect performance under the complex conditions such as the inversion of heart beating, the falling off of the electrodes, the excursion of base line and so on.展开更多
This paper proposes a different method to eliminate base wander and power line interference in electrocardiogram, which introduces the integer coefficient filter theory and gives the detail for designing digital filte...This paper proposes a different method to eliminate base wander and power line interference in electrocardiogram, which introduces the integer coefficient filter theory and gives the detail for designing digital filter to remove these two normal noise signals. Signal from the MIT-BIH electrocardiogram database was used to test the performance of the filter. From the test results, the performance of the digital filer is reDT good. The filter coefficient is an integer number, therefore, the filtering algorithm can be successfully implemented on the microprocessor.展开更多
文摘目的 为快速准确地测算P波离散度，研究和探讨一种实用的计算机辅助测算方法。方法 对12导联同步描记心电图进行计算机数字处理，将P波放大10－20倍，利用人工标志点识别和软件测得Pmax和Pd。结果 对43例阵发性房颤患者和46例无房颤者进行Pd/Pmax的测定与对照，房颤组两项指标均显著增大（Pmax：131.2±7.2ms vs 94.0±6.2ms;Pd:53.2±7.4ms vs 25.7±7.8ms;P<0.001）。结论 计算机辅助放大P波测定法具有测算准确，操作简便等优点。
基金sponsored by NSFC(Grant No.40574030)CNPC research project(Grant No.06A30102)
文摘In this paper, we obtained three dimensional digital cores using X-ray CT to describe the rock microstructure and applied the open morphology algorithm to simulate oil and formation water distribution in the pore space at different water saturations during the oil-displacing water flood process. The resistivity, formation factor, and resistivity index of rocks were calculated using the finite element method （FEM） and we studied the effect of rock wettability on electrical properties. The numerical simulation results indicate that the simulated formation factor and resistivity index of the water wet rock agrees well with experiments over the whole range of water saturation and extends the traditional resistivity experiment. The rock wettablilty has a large influence on the rock resistivity index. The resistivity and saturation exponent of oil wet rock are obviously larger than three of water wet rock.
文摘A new model based on dyadic differential wavelet was developed for detecting the R peak in Holter ECG signal according to the design of data mining. The Mallat recursive filter algorithm was introduced to calculate wavelet and optimize the detection algorithm which is based on the equivalent filter technique. The detection algorithm has been verified by MIT arrhythmia database with a high efficiency of 99%. After optimization, the algorithm was put into clinical experiment and tested in the Air Force Hospital in Tianjin for about two months. After about 108 hearts beating test of more than 100 patients, the total efficient detection rate has reached 97%. Now this algorithm module has been applied in business software and shows perfect performance under the complex conditions such as the inversion of heart beating, the falling off of the electrodes, the excursion of base line and so on.
文摘This paper proposes a different method to eliminate base wander and power line interference in electrocardiogram, which introduces the integer coefficient filter theory and gives the detail for designing digital filter to remove these two normal noise signals. Signal from the MIT-BIH electrocardiogram database was used to test the performance of the filter. From the test results, the performance of the digital filer is reDT good. The filter coefficient is an integer number, therefore, the filtering algorithm can be successfully implemented on the microprocessor.
