Optimization of the Gaussian Kernel Extended by Binary Morphology for Text Line Segmentation

In this paper, an approach for text line segmentation by algorithm with the implementation of the Gaussian kernel is presented. As a result of algorithm, the growing area around text is exploited for text line segmentation. To improve text line segmentation process, isotropic Gaussian kernel is extended by dilatation. Furthermore, algorithms with isotropic and extended Gaussian kernels are examined and evaluated under different text samples. Results are given and comparative analysis is made for these algorithms. From the obtained results, optimization of the parameters defining extended Gaussian kernel dimension is proposed. The presented algorithm with the extended Gaussian kernel showed robustness for different types of text samples

Active and passive-source seismic imaging for exploration of deep-seated massive sulphide mineralization in the Zinkgruvan mine, south-central Sweden

[EN]This communication presents the acquisition of active and passive source seismic data in the Zinkgruvan mine in Sweden in an effort to develop highly resolved and cost-effective exploration method

Investigating the use of 3-D full-waveform inversion to characterize the host rock at a geological disposal site

The U.K. government has a policy to dispose of higher activity radioactive waste in a geological disposal facility (GDF), which will have multiple protective barriers to keep the waste isolated and to ensure no harmful quantities of radioactivity are able to reach the surface. Currently no specific GDF site in the United Kingdom has been chosen but, once it has, the site is likely to be investigated using seismic methods. In this study, we explore whether 3-D full-waveform inversion (FWI) of seismic data can be used to map changes in physical properties caused by the construction of the site, specifically tunnel-induced fracturing. We have built a synthetic model for a GDF located in granite at 1000 m depth below the surface, since granite is one of the candidate host rocks due to its high strength and low permeability and the GDF could be located at such a depth. We use an effective medium model to predict changes in P-wave velocity associated with tunnel-induced fracturing, within the spatial limits of an excavated disturbed zone (EdZ), modelled here as an increase in fracture density around the tunnel. We then generate synthetic seismic data using a number of different experimental geometries to investigate how they affect the performance of FWI in recovering subsurface P-wave velocity structure. We find that the location and velocity of the EdZ are recovered well, especially when data recorded on tunnel receivers are included in the inversion. Our findings show that 3-D FWI could be a useful tool for characterizing the subsurface and changes in fracture properties caused during construction, and make a suite of suggestions on how to proceed once a potential GDF site has been identified and the geological setting is known

The Effects of the Acute Hypoxia to the Fundamental Frequency of the Speech Signal

When people that live at the small altitudes (up to 400 m above the sea level) climb on the mountain, they are exposed to the effects of an acute hypoxia. As a consequence, theirs oxygen concentration decreases in the tissue. This paper presents the analysis of the acute hypoxia effects to the speech signal at the altitudes up to 2600 m above the sea level. For the experiment, the articulation of vowels (A, E, I, O, U) from the test group of persons was recorded at different altitudes, which creates the speech signal database. The speech signal from database is processed by the original algorithm. As the results, the fundamental frequency and the energy of dissonant intervals of speech signal are obtained. Furthermore, the acute hypoxia effect to the energy distribution in the dissonant intervals of the speech signal is analyzed. At the end, the comparative analysis of the acute hypoxia effects shows that the level of the hypoxia can be determined by the change of the fundamental frequency and the energy of the dissonant intervals of speech signal. Hence, it is possible to bring conclusions about the degree of hypoxia, which in many situations can be of importance for avoiding catastrophic consequences

The Effects of the Active Hypoxia to the Speech Signal Inharmonicity

When the people are climbing on the mountain, they are exposed to decreased oxygen concentration in the tissue, which is commonly called the active hypoxia. This paper addressed the problem of an acute hypoxia that affects the speech signal at the altitude up to 2500 m. For the experiment, the speech signal database that contains the articulation of vowels was recorded at different alti¬tudes. This speech signal was processed by the originally developed algorithm, which extracted the fundamental frequency and the inharmonicity coefficient. Then, they were subjected to the analysis in order to derive the effects of the acute hypoxia. The results showed that the hypoxia level can be determined by the change of the inharmonicity coefficient. Accordingly, the degree of hypoxia can be estimated

Data-driven weathering layer statics for hardrock imaging: Solutions based on first-breaks and surface waves

Seismic methods are routinely used for hardrock imaging and mineral-exploration purposes. However, hardrock seismic data requires careful processing, where weathering layer - refraction static corrections have shown to be of great importance for successful imaging. In our study, six differently obtained data-driven weathering layer static solutions are analyzed and compared using a seismic dataset from a mining site in Sweden. Three of the six approaches utilize first-breaks and are based on (1) the standard refraction-inversion method (RI), (2) the application of the RI after adding additional first-breaks via supervirtual seismic interferometry (SVSI), and (3) a tomography-based static solution (Tomostatics). The other three approaches employ surface-waves and are based on (4) the direct transformation of SW dispersion curves, (5) joint inversion of dispersion curves as well as first-breaks and (6) surface-wave tomography. All tested methods were successful in enhancing coherency of the main ore body reflection. A crosscutting reflection can also be seen following the first-break based refraction statics, with highest coherency seen after the application of the SVSIenhanced RI refraction statics. The examples presented suggest that these methods can be complementary and in the absence of notable first-breaks, surface waves can be utilized to estimate weathering layer static corrections

Active and passive-source seismic imaging for exploration of deep-seated massive sulphide mineralization in the Zinkgruvan mine, south-central Sweden

EGU General Assembly in Vienna, Austria, 7–12 April 2019Population growth, together with overall improvement of life standards, greater level of environmental awareness and energy transition towards green technologies, result in globally increasing demand for mineral resources on a yearly basis. Considering that most of the shallow large-scale deposits have likely already been explored and mined out (or are being mined), there is a great interest to explore for deeper-seated deposits. For this purpose, the SIT4ME project, through EIT Raw Material Program was established, aiming to promote, improve and further establish seismic methods for mineral exploration in hard rock environments. In November 2018, a multi-method seismic dataset was acquired in the Zinkgruvan mining area in the Bergslagen mineral province of Sweden. Both active (32t seismic vibrator truck as source) and passive data were acquired using a combination of sparse 3D grid and dense 2D profiles in an area of approximately 6 km2 enabling reasonable 3D subsurface illumination. For the data acquisition, a total of 1300 receivers were used across the study area, distributed along ten 2D-crooked-seismic lines and in a 3D mesh. This provided us with a comprehensive dataset, which would be used for a multitude of processing and imaging approaches. The objectives are to image any deep (> 500 m depth) massive sulphide mineralization and structures hosting them within this complex three-dimensionally deformed hard rock setting. Here, we present the acquisition setup, preliminary reflection seismic processing results obtained from active part of the dataset