在网络世界中,网际互连协议(Internet Protocol,IP)承载网扮演着信息流动的骨干角色,其运行表现和服务水准至关重要。文章详细探讨了IP承载网中服务质量(Quality of Service,QoS)策略的设计与优化方法,重点涵盖分类服务与标记、流量控...在网络世界中,网际互连协议(Internet Protocol,IP)承载网扮演着信息流动的骨干角色,其运行表现和服务水准至关重要。文章详细探讨了IP承载网中服务质量(Quality of Service,QoS)策略的设计与优化方法,重点涵盖分类服务与标记、流量控制与优先级队列管理以及链路和节点策略的具体实现。通过流量分析与预测、智能资源分配与调度、动态策略调整以及故障检测与容错机制,提出一系列提升网络性能和用户体验的有效措施。展开更多
A geophysical survey was conducted in the Kelle-Bidjocka village, Messondo subdivision, in the Centre Region, Cameroon. The data acquisition was made by combining Schlumberger profiling and electrical soundings along ...A geophysical survey was conducted in the Kelle-Bidjocka village, Messondo subdivision, in the Centre Region, Cameroon. The data acquisition was made by combining Schlumberger profiling and electrical soundings along six (06) profiles of 1500 m in length for a total of 64 geoelectrical stations’ survey conducted through a variable mesh 100 m × 200 m, or 100 m × 300 m. The equipment used is the DC resistivimeter Syscal Junior 48 (Iris Instrument). Processing and modelling of field data are made by using the Res2Dinv, Qwseln and Surfer software. The investigation methods used are electrical resistivity (DC) and induced polarization (IP) methods. The analyses and interpretations have helped to highlight areas of weakness or conductive discontinuities (fractures, faults, shear zones, etc.) in Precambrian gneiss formations, sometimes undergoing weathering processes. They identify the weathering or mineralogical accumulation horizons, the most promising is a mineralization channel identified in the NE-SW direction. The highlighted mineralization is characterized by strong gradients of chargeability or polarization. Samples and other geological evidences observed in the area are used to associate the most polarizable structures with ferriferous formations. Weakly polarizable and particularly conductive backgrounds identified by the inverse pseudo-sections are thought to be sulphate minerals or groundwater targets for future hydrogeological studies.展开更多
In this paper the authors propose the natural field induced polarization (IP) method and present the way to pick up IP effect. The relations between the object and anomaly are studied by taking field experiments as ex...In this paper the authors propose the natural field induced polarization (IP) method and present the way to pick up IP effect. The relations between the object and anomaly are studied by taking field experiments as examples. The effectiveness and usability of the method are testified.展开更多
To achieve the current study, geoelectrical surveys along six (06) profiles of 4 km long in a 100 m × 200 m grid defined according to the triangulation principle in the Ngoura area (Tindikala-Boutou villages) hav...To achieve the current study, geoelectrical surveys along six (06) profiles of 4 km long in a 100 m × 200 m grid defined according to the triangulation principle in the Ngoura area (Tindikala-Boutou villages) have been made through electrical sounding and profiling following Schlumberger array. The instrument is the resistivimeter Syscal Junior 48 (IRIS Instrument) which uses the electrical current. The data have been processed and modelled with Res2Dinv and Winsev softwares then interpolated with Surfer software. Electrical methods used are the Direct current (DC) and the Induced Polarization (IP). Interpretation and analyses of results from each investigation method highlight weak zones or conductive discontinuities and mineralized zones. Conductive zones have been identified as shear zones within granitic structures of the Precambrian basement, according to the geologic and tectonic background of the area. The structural trend of these shear zones is E-W. The mineralization within it is N-S and characterized by high values of chargeability, essentially in the eastern part of the area under study. This mineralization proves the presence of metalliferous or sulphide heaps disseminated in weathered quartz veins which cross shear zones. Also, the poor mineralization and conductive structures in shear zones characterize the groundwater zones. The intense activities of gold washers encountered in the area enable to link that mineralization to gold within quartz veins. The near surface gold mineralization is eluvial or alluvial, and in depth this mineralization is primary.展开更多
A geophysical investigation of subsurface structures using the Syscal Junior 48 resistivity-meter was conducted in Ngoura subdivision (East Cameroon) following a combined geoelectrical direct current (DC) approach inv...A geophysical investigation of subsurface structures using the Syscal Junior 48 resistivity-meter was conducted in Ngoura subdivision (East Cameroon) following a combined geoelectrical direct current (DC) approach involving Resistivity and IP methods. This investigation was allowed to collect data on forty-five (45) profiling lines at three acquisition levels (AB = 100 m, MN = 10 m;AB = 200 m, MN = 20 m and AB = 500 m, MN = 50 m) and two electric panels L1 and L4, using the Schlumberger array. Processing, modeling and interpretation of data collected using the Winsev, Res2Dinv and Surfer software helped in highlighting a conductive and strongly mineralized discontinuity in granite formations, which lined up with the NE-SW Kadei tectonic line. It extends beyond 100 m depth over an average width of 600 m. The mineralization associated with this discontinuity is identified by a high concentration of disseminated metalliferous minerals in quartz or pegmatite veins. The mining reconnaissance works in the study area and those of several authors have characterized this anomaly to a lode gold quartz or large pegmatite. The results of this study correlate with geological and tectonic data for the region marked by NE-SW Kadei tectonic line. Therefore, they confirm the reliability of a geoelectrical DC investigation method combining Resistivity and IP to the identification of ore bodies.展开更多
During transient electromagnetic method （TEM） exploration of a copper mine, we detected the late-channel TEM signal reversal phenomenon （a voltage change from positive to negative） caused by the influence of the i...During transient electromagnetic method （TEM） exploration of a copper mine, we detected the late-channel TEM signal reversal phenomenon （a voltage change from positive to negative） caused by the influence of the induced polarization （IP） effect, which affects the depth and precision of the TEM detection. The conventional inversion method is inefficient because it is difficult to process the data. In this paper, the Cole-Cole model is adopted to analyze the effect of Dc resistivity, chargeability, time constant, and frequency exponent on the TEM response in an homogeneous half space model. Singular Value Decomposition （SVD） is used to invert the measured TEM data, and the Dc resistivity, chargeability, time constant and frequency exponent were extracted from the measured TEM data in the mine area. The extracted parameters are used for interpreting the detection result as a supplement. This reveals why the TEM data acquired in the area has a low resolution. It was found that the DC resistivity and time constant do not significantly change the results, however, the chargeability and frequency exponent have a significant effect. Because of these influences, the SVD method is more accurate than the conventional method in the apparent resistivity profile. The area of the copper mine is confined accurately based on the SVD inverted data. The conclusion has been verified by drill and is identical to the practical geological situation.展开更多
文摘在网络世界中,网际互连协议(Internet Protocol,IP)承载网扮演着信息流动的骨干角色,其运行表现和服务水准至关重要。文章详细探讨了IP承载网中服务质量(Quality of Service,QoS)策略的设计与优化方法,重点涵盖分类服务与标记、流量控制与优先级队列管理以及链路和节点策略的具体实现。通过流量分析与预测、智能资源分配与调度、动态策略调整以及故障检测与容错机制,提出一系列提升网络性能和用户体验的有效措施。
文摘A geophysical survey was conducted in the Kelle-Bidjocka village, Messondo subdivision, in the Centre Region, Cameroon. The data acquisition was made by combining Schlumberger profiling and electrical soundings along six (06) profiles of 1500 m in length for a total of 64 geoelectrical stations’ survey conducted through a variable mesh 100 m × 200 m, or 100 m × 300 m. The equipment used is the DC resistivimeter Syscal Junior 48 (Iris Instrument). Processing and modelling of field data are made by using the Res2Dinv, Qwseln and Surfer software. The investigation methods used are electrical resistivity (DC) and induced polarization (IP) methods. The analyses and interpretations have helped to highlight areas of weakness or conductive discontinuities (fractures, faults, shear zones, etc.) in Precambrian gneiss formations, sometimes undergoing weathering processes. They identify the weathering or mineralogical accumulation horizons, the most promising is a mineralization channel identified in the NE-SW direction. The highlighted mineralization is characterized by strong gradients of chargeability or polarization. Samples and other geological evidences observed in the area are used to associate the most polarizable structures with ferriferous formations. Weakly polarizable and particularly conductive backgrounds identified by the inverse pseudo-sections are thought to be sulphate minerals or groundwater targets for future hydrogeological studies.
基金The study is supported by the National Natural Science Foundation of China
文摘In this paper the authors propose the natural field induced polarization (IP) method and present the way to pick up IP effect. The relations between the object and anomaly are studied by taking field experiments as examples. The effectiveness and usability of the method are testified.
文摘To achieve the current study, geoelectrical surveys along six (06) profiles of 4 km long in a 100 m × 200 m grid defined according to the triangulation principle in the Ngoura area (Tindikala-Boutou villages) have been made through electrical sounding and profiling following Schlumberger array. The instrument is the resistivimeter Syscal Junior 48 (IRIS Instrument) which uses the electrical current. The data have been processed and modelled with Res2Dinv and Winsev softwares then interpolated with Surfer software. Electrical methods used are the Direct current (DC) and the Induced Polarization (IP). Interpretation and analyses of results from each investigation method highlight weak zones or conductive discontinuities and mineralized zones. Conductive zones have been identified as shear zones within granitic structures of the Precambrian basement, according to the geologic and tectonic background of the area. The structural trend of these shear zones is E-W. The mineralization within it is N-S and characterized by high values of chargeability, essentially in the eastern part of the area under study. This mineralization proves the presence of metalliferous or sulphide heaps disseminated in weathered quartz veins which cross shear zones. Also, the poor mineralization and conductive structures in shear zones characterize the groundwater zones. The intense activities of gold washers encountered in the area enable to link that mineralization to gold within quartz veins. The near surface gold mineralization is eluvial or alluvial, and in depth this mineralization is primary.
文摘A geophysical investigation of subsurface structures using the Syscal Junior 48 resistivity-meter was conducted in Ngoura subdivision (East Cameroon) following a combined geoelectrical direct current (DC) approach involving Resistivity and IP methods. This investigation was allowed to collect data on forty-five (45) profiling lines at three acquisition levels (AB = 100 m, MN = 10 m;AB = 200 m, MN = 20 m and AB = 500 m, MN = 50 m) and two electric panels L1 and L4, using the Schlumberger array. Processing, modeling and interpretation of data collected using the Winsev, Res2Dinv and Surfer software helped in highlighting a conductive and strongly mineralized discontinuity in granite formations, which lined up with the NE-SW Kadei tectonic line. It extends beyond 100 m depth over an average width of 600 m. The mineralization associated with this discontinuity is identified by a high concentration of disseminated metalliferous minerals in quartz or pegmatite veins. The mining reconnaissance works in the study area and those of several authors have characterized this anomaly to a lode gold quartz or large pegmatite. The results of this study correlate with geological and tectonic data for the region marked by NE-SW Kadei tectonic line. Therefore, they confirm the reliability of a geoelectrical DC investigation method combining Resistivity and IP to the identification of ore bodies.
基金supported by the National Technology R&D Program in the 11th Five year Plan of China(No.2007BAQ00168-1-1)the National Natural Science Foundation of China(No. 41103052/D0309)the Shanxi Province Excellent Graduate Innovation Program(No. 20113038)
文摘During transient electromagnetic method （TEM） exploration of a copper mine, we detected the late-channel TEM signal reversal phenomenon （a voltage change from positive to negative） caused by the influence of the induced polarization （IP） effect, which affects the depth and precision of the TEM detection. The conventional inversion method is inefficient because it is difficult to process the data. In this paper, the Cole-Cole model is adopted to analyze the effect of Dc resistivity, chargeability, time constant, and frequency exponent on the TEM response in an homogeneous half space model. Singular Value Decomposition （SVD） is used to invert the measured TEM data, and the Dc resistivity, chargeability, time constant and frequency exponent were extracted from the measured TEM data in the mine area. The extracted parameters are used for interpreting the detection result as a supplement. This reveals why the TEM data acquired in the area has a low resolution. It was found that the DC resistivity and time constant do not significantly change the results, however, the chargeability and frequency exponent have a significant effect. Because of these influences, the SVD method is more accurate than the conventional method in the apparent resistivity profile. The area of the copper mine is confined accurately based on the SVD inverted data. The conclusion has been verified by drill and is identical to the practical geological situation.
