Teeth segmentation of dental periapical radiographs based on local singularity analysis

2014 ◽  
Vol 113 (2) ◽  
pp. 433-445 ◽  
Author(s):  
P.L. Lin ◽  
P.Y. Huang ◽  
P.W. Huang ◽  
H.C. Hsu ◽  
C.C. Chen
Keyword(s):  
Singularity Analysis ◽  
Local Singularity

scholarly journals A novel iterative approach for mapping local singularities from geochemical data

2007 ◽  
Vol 14 (3) ◽  
pp. 317-324 ◽  
Author(s):  
◽  
◽  
◽  
Keyword(s):  
Large Scale ◽  
Mineral Exploration ◽  
Singularity Analysis ◽  
Geochemical Data ◽  
Iterative Approach ◽  
Scale Invariant ◽  
Singularity Index ◽  
Parameter Estimations ◽  
Singular Functions ◽  
Local Singularity

Abstract. There are many phenomena in nature, such as earthquakes, landslides, floods, and large-scale mineralization that are characterized by singular functions exhibiting scale invariant properties. A local singularity analysis based on multifractal modeling was developed for detection of local anomalies for mineral exploration. An iterative approach is proposed in the current paper for improvement of parameter estimations involved in the local singularity analysis. The advantage of this new approach is demonstrated with de Wijs's zinc data from a sphalerite-quartz vein near Pulacayo in Bolivia. The semivariogram method was used to illustrate the differences between the raw data and the estimated data by the new algorithm. It has been shown that the outcome of the local singularity analysis consists of two components: singularity component characterized by local singularity index and the non-singular component by prefractal parameter.

scholarly journals Comparison of Methods for Determining the Thresholds of Geochemical Anomalies and the Prospecting Direction—A Case of Gold Deposits in the Gouli Exploration Area, Qinghai Province

Minerals ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 368 ◽  
Author(s):  
Dingjie Chen ◽  
Junhao Wei ◽  
Wenhui Wang ◽  
Wenjie Shi ◽  
Huan Li ◽  
...  
Keyword(s):  
Principal Component ◽  
Singularity Analysis ◽  
Cumulative Frequency ◽  
Analysis Method ◽  
Robust Principal Component Analysis ◽  
Frequency Method ◽  
Qinghai Province ◽  
Geochemical Anomalies ◽  
Local Singularity ◽  
Exploration Area

Geochemical anomalies play an important role in mineral exploration, because they are closely related to the formation of ore deposits. In this paper, the Au in the geochemical samples of 1:50,000 stream sediments in the Gouli exploration area, Qinghai Province, is selected as an example. The cumulative frequency method, local singularity analysis, and exploration data analysis method are used to process the Au data and determine the abnormal thresholds. Robust principal component analysis is used to explore the elemental associations. Among them, the effect of local singularity analysis is the best and it delineates the weak geochemical anomalies not delineated by cumulative frequency method and exploration data analysis method, which shows its superiority. Robust principal component analysis shows that Sb, W, and As are closely related to Au mineralization. Three anomalous areas are delineated in the Gouli exploration area. Gold ore-body is found to occur within anomaly area I. The other anomalous areas are highly consistent with abnormal elemental composition of Sb, W, and As. Moreover, these two areas are extremely conformable with the high-value areas determined by the binary state method. The optimality of the three methods are compared comprehensively, it is pointed out that it is more reasonable to use the local singularity analysis to determine the abnormal threshold. The anomaly areas II and III of Au determined by local singularity analysis have shown great potential for prospecting.

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