复杂数据探勘的道德风险与规训机制

立足广域共享信息资源池和聚汇机器学习算法的实时且廉价的可视化数据探勘在充分展现出深度发掘数据资产价值剩余、创新优化公共服务能力、有序增进社交福祉等强劲实力的同时,逐渐暴露出直观探勘干扰自由表达、智数决策破坏平等格局、数据鸿沟扰乱竞争秩序等严重背离基本人权与经济目标的道德风险。亟待在弘扬超越异质群体不同诉求的共在、共生、共享、共荣之共同道德精神的基础上,全面执行安全、自主、适应性和利益协调等具体道德规训。

网格空间资料探勘应用于犯罪预测之研究

台湾警察机关自1970年代起陆续将各项警政资料,包括治安、交通、犯罪侦查等相关数据建立信息系统,目前已累积数量庞大的治安大数据。善用信息科技强大的数据处理、统计分析及探勘功能,挖掘隐藏于大数据的知识,以提供决策所需的辅助信息,不但有助于掌握问题及研拟因应作为,而且经由趋势分析与模式归纳学习,更可以进一步预测未来,作为规划因应方案的参考。此项研究搜集整理台湾新北市刑案记录数据,运用网格分析法,定义网格毒品犯罪形态特征及设计毒品犯罪预测向量,并以数据探勘软件套件进行犯罪预测实验。结果显示,以网格分析方法及大数据探勘预测犯罪之平均效能,明显优于传统运用经验法则的犯罪预测方法。

The anti-correlation method for removing harmonic distortion in vibroseis slip-sweep data

The slip-sweep technique is one of the high-efficiency, high-fidelity, and environmental vibroseis seismic prospecting techniques which consists of a vibrator group sweeping without waiting for the previous group＇s sweep to terminate. The cycle time can be reduced drastically and hence the production efficiency can be increased significantly but harmonic distortion of one sweep will leak into the record of the other sweep. In this paper, we propose an anti-correlation method for removing harmonic distortion in vibroseis data. This method is based on decomposition of the ground force signal into fundamental and harmonic components. Then the corresponding anti-correlation operator can be computed to estimate the energy of each harmonic after correlating the vibroseis data with the corresponding harmonic component. Finally, the vibroseis harmonic noise to be removed can be obtained by subtracting the extracted harmonic noise from the traces of the previous group＇s sweep. The advantage of the proposed method is that it can process both uncorrelated and correlated vibroseis seismic data. Moreover, the algorithm is simple, stable, and computationally fast. Especially, the significant contribution of this method is a considerable reduction in the harmonic without any alteration of the desired signals. The method was tested on both synthetic and field data sets to validate the good harmonic noise suppression results.

Separation of P. and SV-wavefields from multi-componen seismic data

In multi-component seismic exploration, the horizontal and vertical components both contain P- and SV-waves. The P- and SV-wavefields in a seismic record can be separated by their horizontal and vertical displacements when upgoing P- and SV-waves arrive at the sea floor. If the sea floor P wave velocity, S wave velocity, and density are known, the separation can be achieved in ther-p domain. The separated wavefields are then transformed to the time domain. A method of separating P- and SV-wavefields is presented in this paper and used to effectively separate P- and SV-wavefields in synthetic and real data. The application to real data shows that this method is feasible and effective. It also can be used for free surface data.

Application of Catastrophe Theory in 3D Seismic Data Interpretation of Coal Mine

In order to detect fault exactly and quickly, cusp catastrophe theory is used to interpret 3D coal seismic data in this paper. By establishing a cusp model, seismic signal is transformed into standard form of cusp catastrophe and catastrophe parameters, including time-domain catastrophe potential, time-domain catastrophe time, frequency-domain catastrophe potential and frequency- domain degree, are calculated. Catastrophe theory is used in 3D seismic structural interpretation in coal mine. The results show that the position of abnormality of the catastrophe parameter profile or curve is related to the location of fault, and the cusp catastrophe theory is effective to automatically pick up geology information and improve the interpretation precision in 3D seismic data.

Characteristics analysis on high density spatial sampling seismic data

China＇s continental deposition basins are characterized by complex geological structures and various reservoir lithologies. Therefore, high precision exploration methods are needed. High density spatial sampling is a new technology to increase the accuracy of seismic exploration. We briefly discuss point source and receiver technology, analyze the high density spatial sampling in situ method, introduce the symmetric sampling principles presented by Gijs J. O. Vermeer, and discuss high density spatial sampling technology from the point of view of wave field continuity. We emphasize the analysis of the high density spatial sampling characteristics, including the high density first break advantages for investigation of near surface structure, improving static correction precision, the use of dense receiver spacing at short offsets to increase the effective coverage at shallow depth, and the accuracy of reflection imaging. Coherent noise is not aliased and the noise analysis precision and suppression increases as a result. High density spatial sampling enhances wave field continuity and the accuracy of various mathematical transforms, which benefits wave field separation. Finally, we point out that the difficult part of high density spatial sampling technology is the data processing. More research needs to be done on the methods of analyzing and processing huge amounts of seismic data.

Methods to increase the depth and precision of transient Rayleigh wave exploration

In order to increase the exploration depth of Rayleigh wave, new idea that dif-ferent from the former principles in data acquisition was applied. Suitable data acquisition parameter was given out on the basis of large amount of experiments. By reducing the group interval, the low frequency signal are enhanced instead of been attenuated. Fur-thermore, to solve the problem that the precision of Rayleigh wave exploration method count much to the signal-to-noise ratio, some preprocessing methods were put forward. By using zero shift rectifying, digital F-K filtering and cutting, noises can be effectively eliminated.

Estimation of correction coefficients for measured coal bed methane contents

Improving the accuracy and precision of coal bed methane(CBM) estimates requires correction of older data from older coal exploration surveys to newer standards.Three methods,the depth gradient method,the contour aerial weight method,and the well-point aerial weight method,were used to estimate the correction coefficient required to predict CBM gas content from coal exploration data.The data from the Nos.3 and 15 coal seams provided the coal exploration data while the CBM exploration stages within the X1 well block located in the southern part of the Qinshui Basin provided the data obtained using newer standards.The results show the correction coefficients obtained from the two aerial weight methods are similar in value but lower than the one obtained from the depth gradient method.The three methods provide similar results for the Nos.3 and 15 seams in that the correction factor is lower for the former seam.The results from the depth gradient method taken together with the coal seam burial depth and the coal rank suggest that variations in the correction factor increase linearly along with coal seam burial depth and coal rank.The correlation obtained can be applied to exploration and the evaluation of coal bed gas resources located in coalfields.

Application examples of 3D visual interpretation technology in Dagang Oilfield

3D visualization technology is a new seismic interpretation technology that is completely different from traditional seismic data interpretation technologies. This method takes geologic bodies or any 3D region of interest as a unit and integrates the points, lines, and planes of the bodies to make a 3D visual interpretation. This technology can be integrated with the coherence technique to interpret complex faults. Spatial domain automatic horizon tracing can accurately determine structural features. Target sculpting can determine the spatial dimensions and depth extent of perspective 3D lithology bodies using inversion data. I applied this technology to the interpretation of the complex block structures in the Guanxi area of Dagang Oilfield and the prediction of subtle reservoirs in the western slope of the Qinan sag with good results. This study indicated that the visual interpretation technology can be widely and effectively applied in oil field development and to improve the exploration success ratio.

Neural Network Applications in Petroleum Exploration Based on Statistical Space Mapping

In this paper, we propose the statistical space mapping thought and classify the seismic body space throughlithology space clustering combining to the actual application background of petroleum exploration. A new method ofstratum petroleum recognition based on neural network was set up through the foundation of the data mapping relationbetween log and seismic body. It can break a new path for recognition petroleum using both log and seismic data. Andthis method has been validated in the practical data analysis in Liaohe oil field.

Inverse Spline Interpolation for All-time Resistivity of Central-Loop TEM

A convenient numerical calculation method (inverse spline interpolation) for all-time apparent resistivity intransient electromagnetic method (TEM) is proposed in this paper. Characteristic of early and late normalized inductiveelectromotive force was investigated. According to the turning point, the transient process is divided into the earlyphase, the turning point, and the late phase. Afterwards, apparent resistivity is obtained through inverse spline interpo-lation in the early and the late phases, respectively. Finally, the resistivities of the early-time and the late-time wereconnected together by the turning point. The result shows that the inverse spline method is feasible and the method alsolays a foundation for initial model construction in the TEM automatic inversion.

Prediction of Coal Seam Methane Enriched Areas Using Seismic Data

All coal mine disasters are dynamic geological phenomenon and affected by many factors. However, locating the enriched areas of CSM (coal seam methane) may be the precondition for the successful prediction of such disasters. Traditional methods of investigating CSM enriched areas use limited data and only consider a few important factors. Their success rate is low and cannot meet practical needs. In this paper, an alternative method is proposed. The proce- dure is given as follows: 1) fracture attributes derived from azimuth variations of P-wave data in coal seams and wall rocks can be extracted; 2) AVO attributes, such as the intercept P and gradient G parameters can be extracted from different azimuths from 3D seismic data; 3) seismic cubes can be inverted and the relative attributes of imped- ance cubes can be extracted; 4) using a GIS platform, multi-source information can be obtained and analyzed; these include fracture attributes of coal seams and wall rocks, the thickness of coal seams, the distribution of faults and structures, the depth of coal seams, the inclination and exposure of coal seams and the coal rank. Through this processing procedure, methane enriched areas can be systematically detected.

Application of 3D Seismic Data Inversion to Coal Mining Prospecting

Seismic inversion is one of the most important methods for lithological prospecting . Seismic data with lowresolution is converted into impedance data of high resolution which can reflect the geological structure by inversionThe inversion technique of 3D seismic data is discussed from both methodological and theoretical aspects, and the in-version test is also carried out using actual logging data. The result is identical with the measured data obtained fromroadway of coal mine. The field tests and research results indicate that this method can provide more accurate data foridentifying thin coal seam and minor faults.

Focus projection of the parabolic radon transform and multiple waves separator, elimination

Based on the scalar wave equation, making use of the ray approximation of the reflected seismic data (CMP or CSP gathers), the authors derive respectively the projection function of the primary waves and multiple waves at the near offset (CMP or CSP gathers) in the parabolic Radon transform(PRT)domain. From the geometric point, the authors prove that the energy of the reflection still distributes along hyperbola which has higher curvature in the PRT domain and becomes some energy masses. So the primary waves and the multiple waves which interweave each other in ( x, t ) domain can be completely separated, which helps the multiple waves eliminated by filtering or muting. It is important for the analysis of velocity and the separator and elimination of multiple waves.

Seismic Data Processing and Interpretation on the Loess Plateau, Part1: Seismic Data Processing

Branching river channels and the coexistence of valleys, ridges, hiils, and slopes＇as the result of long-term weathering and erosion form the unique loess topography. The Changqing Geophysical Company, working in these complex conditions, has established a suite of technologies for high-fidelity processing and fine interpretation of seismic data. This article introduces the processes involved in the data processing and interpretation and illustrates the results.

Application of Fractional Fourier Transform in seismic data denoising

Data processing is a basic and crucial factor in seismic exploration,which can influence the effect of subsequent processing directly. Thus the selection of appropriate method for data processing is one of the most important tasks throughout the work. By simulating,the authors analyze and compare Fractional Fourier Transform( FRFT) and Wigner-Ville distribution( WVD),then summarize the similarities and advantages and disadvantages of the two methods. The results reveal that FRFT is more effective and suitable for application in seismic exploration than WVD.

Research on the Historical Data of the 1585 A. D. South Chaoxian Earthquake and Its Seismogenic Structure

In 1585,a MS5 3/4 earthquake occurred in the south of Chaoxian county,Anhui Province. The parameters of this earthquake were reported differently in various versions of earthquake catalogues. According to detailed textual research on the historic records of this earthquake,the epicenter location of the earthquake was further confirmed by means of seismo-geological field investigations in the Chaohu-Tongling region along the western Yangtze River valleys. Shallow seismic prospecting and drilling methods were applied in studying the buried fault. The possibility of the existence of seismogenic faults and fault activity in the western Yangtze River area were analyzed in depth,and the causative tectonic background of the 1585 MS5 3/4 south Chaoxian earthquake was studied. The results of this study indicate that the Yanjiaqiao-Fengshahu fault,which was active in the early to mid-Pleistocene,is possibly the causative structure of this earthquake. To identifying the seismogenic structure of the 1585 south Chaoxian earthquake will help gain more knowledge about the tectonic background of moderate and small earthquake activity in Eastern China.

The Acquisition Technique of High-resolution Seismic Data for the Prospecting of Active Faults

The high-resolution shallow seismic technique can be used for more accurately prospecting the position and property of faults and for the preliminary study of fault activity.The author obtains many high quality stack time sections through the prospecting methods of different seismic sources,different group intervals and different observation systems on the Xiadian fault.These sections clearly display the stratum structure and the structure characteristics from several meters to several hundred meters of the Xiadian fault.The resolutions of the different seismic sources,different group intervals and different observing systems are obtained.The prospecting methods and work parameters applicable for goal stratum of different depths and different accuracy requirements are proposed through the analysis of the stack time sections.This lays a good foundation for raising the prospecting resolution of the fault position and the latest active time of the fault.

Indication to distinguish the burst region of coal gas from seismic data

The velocity of an over-burst coal seam based on laboratory test results. This seam is about 1/3 compared to a normal coal can be considered as a basis to confirm the area of coal and gas burst by seismic exploration technique. Similarly, the simulation result of the theoretical seismic model shows that there is obvious distinction between over-burst coal and normal coal based on the coal reflection＇s travel-time, energy and frequency. The results from the actual seismic data acquired in the coal and gas over-burst cases is consistent with that of the laboratory and seismic modeling; that is, in the coal and gas burst region, seismic reflection travel time is delayed, seismic amplitude is weakened and seismic frequency is reduced. Therefore, it can be concluded that seismic exploration tech- nique is promising for use in distinguishing coal and gas over-burst regions based on the variation of seismic reflection travel time, amplitude and frequency.

Seismic Data Processing and Interpretation on the Loess Plateau, Part 2: Seismic Data Interpretation

The loess plateau covering the North Shaanxi slope and Tianhuan depression consists of a regional monocline, high in the east and low in the west, with dips of less than 1^0, Structural movement in this region was weak so that faults and local structures were not well developed. As a result, numerous wide and gentle noses and small traps with magnitudes less than 50 m were developed on the large westward-dipping monocline. Reservoirs, including Mesozoic oil reservoirs and Paleozoic gas reservoirs in the Ordos Basin, are dominantly lithologic with a small number of structural reservoirs. Single reservoirs are characterized as thin with large lateral variations, strong anisotropy, low porosity, low permeability, and low richness. A series of approaches for predicting reservoir thickness, physical properties, and hydrocarbon potential of subtle lithologic reservoirs was established based on the interpretation of erosion surfaces.