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Earth Resistance for Archaeologists, written by the foremost expert in the field, provides archaeologists with the know-how required to exploit the significant potential of earth resistance methods. A wide variety of possible uses are presented, including cases where earth resistance surveys succeeded in mapping buried archaeological remains that magnetometer surveys were unable to detect. Examples include earth resistance data from many archaeological sites, including in England, Scotland, Nepal, Bangladesh, and more. The archaeological features that can be detected through earth resistance methods are varied, ranging from ditches, pits, and grave cuts to stone and brick foundations, and even include whole landscapes. Whereas area surveys were traditionally the most common earth resistance method, depth profiling and vertical imaging have become well-developed tools that allow electrical depth investigations in three dimensions. Both techniques are described in detail and archaeologists will be able to apply them in their work. Content is equally relevant for environmental investigations.

We have developed a 3-D forward modeling method for the magnetometric resistivity (MMR) technique, specially focusing on the marine MMR method, which utilizes a vertical bipole source and seafloor receivers to measure magnetic field variations. The bipole source generates an artificial electric current between two electrodes: one on the sea surface and another on the seafloor. When computing the electric potential using the relaxation method, while conserving electric current, singularities arise at the electrode locations. To address this issue, we introduce two electrical resistivity structures to mitigate the effects of these singularities and to obtain magnetic field anomalies caused by arbitrary 3-D electrical resistivity anomalies beneath the seafloor. By determining the sign of the magnetic field anomaly, we can infer whether the electrical resistivity of the anomalous body is more conductive or more resistive compared to the surrounding oceanic crust. Furthermore, we demonstrate that increasing the number of bipole sources is more effective in exploring anomalous bodies than increasing the number of receivers.

A fault called as Lembang Fault is known as one of the most potential faults in West Java of Indonesia that could trigger earthquakes with magnitude up to M w 7.0, especially in Bandung Region. This study presents analysis of ground response of Bandung Regency subsoils due to predicted earthquake triggered by Lembang Fault, West Java Province, Indonesia. Site investigation is conducted in the study area. The ground motion analysis is conducted to predict potential ground motion that could happen in the study area. The spectral matching method is employed to generate ground motion in the study area. Furthermore, one-dimensional seismic ground response analysis is performed to observe site response during earthquake. The results show that several sites could undergo amplification and de-amplification. If a M w 7.0 earthquake happens, the damage intensity level varied from VIII to X could happen. The results also indicate that spectral acceleration at ground surface tends to be critical at long period. Therefore, the implementation of seismic design code for earthquake resistance design should be concerned in the study area. In general, the result of this study could deliver a recommendation to local government to consider earthquake in the study area.

As a non-contact method, the transient electromagnetic (TEM) method has the characteristics of high efficiency, small impact of device, no limitation of site range, and high resolution, and is a hot topic in current research. However, the research on the refined data processing method of TEM is lag, which seriously restricts the application in superficial engineering investigation and is a key problem that needs to be solved urgently. The particle swarm optimization (PSO) algorithm and firefly algorithm (FA) were successful swarm intelligence algorithms inspired by nature. However, the accuracy and efficiency of the algorithm restrict its further development. In this paper, the particle moving velocity of FA algorithm is defined according to the concept of particle moving velocity in PSO algorithm, so as to improve the local fast convergence ability of FA algorithm. On this basis, the appropriate velocity of particle movement is improved, so that the improved algorithm can overcome the oscillation problem around the optimal solution and improve the computational efficiency. And finally, an improved PSO-IFA hybrid optimization algorithm (PSO-IFAH) was proposed in the paper. The proposed algorithm can exploit the strong points of both PSO and FA algorithm mechanisms. A typical layered model was established, and the PSO algorithm, FA algorithm, and PSO-IFAH algorithm were applied to inversion calculations. The results show that the PSO-IFAH algorithm improves calculation accuracy by more than 80% and efficiency by over 60% compared to the PSO and FA algorithms, respectively. The PSO-IFAH algorithm also exhibits high inversion accuracy and stability, with superior anti-noise properties compared to the other algorithms. When implemented in ground TEM measurement data processing, the PSO-IFAH algorithm enhances the resolution of anomalies and low-resistance details, aligning well with actual excavation results. This highlights the algorithm’s capability to depict underground electrical structures and karst developments accurately, thereby improving the precision of TEM data processing and interpretation.

Using the 3-D axial anisotropy, the dipping anisotropy, and the azimuthal anisotropy as case studies, we investigated the influence of each anisotropic resistivity element on the magnetotelluric surface responses. To justify the strong and weak influence and edge effect, we have introduced the influence indices for the impedance components, and the edge effect indices for the tipper components. Interestingly, for decoupled modes, we found that ρxx has a strong influence on Zxy, Zyy, and Ty, while ρyy strongly affects Zyx, Zxx, and Tx. The three elements ρzz, ρxz, and ρyz have only a very weak influence on all types of responses. For the coupled mode, ρxx, ρyy, and ρxy display a strong influence on all responses. Based on our studies on the influence of the anisotropic resistivity elements, we design and propose two practical processes to replace the conventional axial, dipping, azimuthal, and general anisotropic inversions. First, the axial or dipping inversion can be approximately decoupled into ρx-mode and ρy-mode inversions. The decoupled mode inversions can be performed either independently and in parallel, or as a joint inversion. Second, since the three resistivity elements always show a weak influence, the general anisotropic inversion can be simplified to just the reduced coupled azimuthal anisotropic inversion with only three resistivity elements as outputs. Both proposed techniques can save a lot of the computational resources. Criteria to choose either the decoupled or coupled modes depend greatly on the magnitudes and distributions of the Zxx and/or Zyy, and Tx and/or Ty responses.

We have developed two novel axial anisotropic inversion codes for magnetotelluric (MT) data: a full axial inversion and a decoupled axial inversion. Both codes are based on the data space Gauss–Newton inversion method used in the WSINV3DMT code, enhanced with OpenMP parallelization and Intel MKL PARDISO direct solver for improved computational efficiency. The full axial inversion searches for three axial anisotropic resistivity elements ρ xx , ρ yy , and ρ zz . Based on our prior influence studies, we identified contrasting influence patterns: ρ xx has a strong influence on Z xy and Z yy , whereas ρ yy has a strong influence on Z yx and Z xx , while ρ zz has negligible impact on all responses. We, therefore, proposed a decoupled axial inversion. This novel technique splits the full axial inversion into two independent modes: ρ xx - and ρ yy -modes. The ρ xx -mode requires just the Z xy and Z yy responses to recover ρ xx , while the ρ yy -mode requires the other two responses. By splitting the inversion, each mode requires half the data parameters and reduces model parameters to one-third compared to the full axial inversion. The substantial parameter reduction is the key factor leading to significantly faster processing times and lower memory requirements. Both codes were validated with the synthetic model. Utilizing OpenMP and direct solvers, the full axial inversion processed 256 MT stations in 65 min per iteration or a total of 195 min for three iterations to converge. The decoupled inversion achieved significantly faster processing, requiring just 32 min per iteration or a total of 96 min to finish the inversion. In addition, the decoupled inversion requires just a fraction of the memory used in the full axial inversion. This makes it practical to operate even on the standard personal computers of current technology. We further applied the decoupled inversion to real MT data acquired in the Northwestern Pacific Ocean. The resulting 3-D inverted ρ xx and ρ yy models support the existence of the anisotropy occurring at 60–120 km depth beneath the ocean floor, in agreement with previous studies. Graphical abstract

Electrical resistance is among the characteristics that fastening systems must meet to ensure the proper functioning of signaling systems in railway infrastructure. The EN 13146-5:2012 standard specifies a laboratory testing method for determining the electrical resistance under wet conditions between running rails provided by a fastening system on steel or concrete sleepers. In urban railway tracks, the electrical resistance of fastening systems affects the stray current; however, there is no standardized electrical resistance measuring method. There is also no definition for the minimum value that the electrical resistance of fastening systems must satisfy to prevent stray currents. For this reason, this paper analysis the possibility of using the standard EN 13146-5:2012 for the measurement and analysis of the electrical resistance of fastening systems in urban railway tracks. In this study, the electrical resistance of different fastening systems used in urban railway tracks was measured. Based on the tests results, the modifications needed in the EN 13146-5 standard for it to be suitable for urban railway tracks were identified. The proposed modifications include the use of a DC current source. The test should be performed on a rail sample fastened to the concrete base, and the current circuit should be closed by the reference electrode installed in the base. Spraying water from nozzles is not applicable for this measurement. The test should be performed under dry conditions and at different water levels (water on the top of the concrete base and on the top of the levelling layer). Different water levels were used to simulate the most common conditions in urban railway tracks built as part of the road surface, where the track-drying process is very slow. The test should not be performed when the rails are immersed in water, because the current flows directly from the rail into the water in such case, and the fastening system has no influence on the measured electrical resistance value. In addition to describing the proposed changes, the calculation of the minimum electrical resistance value that fastening systems in urban railway tracks must satisfy is also presented.

The rise of intelligent buildings in China is based on two reasons. One is that with the reform and opening up, China's national economy has continued to develop rapidly, its overall national strength has been continuously enhanced, and people's living standards have been improved. People urgently need to improve and enhance their working and living environments. Architecture is just one of the important ways to meet this demand. Performance-based seismic design is based on the investment-benefit criterion as a basic principle, reflecting an important change in the seismic design thinking of modern structures, that is, focusing on structural safety from the past. To develop a comprehensive focus on structural performance, safety and economy. It makes the seismic design transition from macroscopically qualitative goals to concretely quantified multiple goals. Designers can choose the required performance goals, which is conducive to the innovation of building structures, using new structural systems, new technologies, and new materials; it is beneficial to adopt different performance goals and earthquake resistance for different fortification intensity, site conditions, and the importance of the building Measures. It is a change in the design concept and plays a significant role in the design and development of engineering structures. This paper explores the characteristics, composition, and design requirements of high-rise intelligent buildings, analyzes their superiority and social benefits, and studies their architectural principles and future development trends. High-rise intelligent buildings were born to meet the higher requirements of office and living environments. It is a combination of architectural art and information technology. It is the four basic elements of structure, system service and optimal combined system management, providing a safe, efficient, comfortable and convenient built environment. At present, only the uncertainty of the load, the strength of the material, the geometric dimensions and the uncertainty of the calculation model are usually considered. For the artificial uncertainty, the complexity and uncertainty of the economic loss estimation due to the complexity of earthquake damage As a result, it is very difficult to accurately estimate economic losses, especially the estimation of indirect losses. Therefore, the establishment of a performance-based reliability optimization decision-making model for high-rise intelligent buildings requires further research and improvement. To build more detailed and specific models for different types of requirements.

We have developed a 3-D forward modeling method for the magnetometric resistivity (MMR) technique, specially focusing on the marine MMR method, which utilizes a vertical bipole source and seafloor receivers to measure magnetic field variations. The bipole source generates an artificial electric current between two electrodes: one on the sea surface and another on the seafloor. When computing the electric potential using the relaxation method, while conserving electric current, singularities arise at the electrode locations. To address this issue, we introduce two electrical resistivity structures to mitigate the effects of these singularities and to obtain magnetic field anomalies caused by arbitrary 3-D electrical resistivity anomalies beneath the seafloor. By determining the sign of the magnetic field anomaly, we can infer whether the electrical resistivity of the anomalous body is more conductive or more resistive compared to the surrounding oceanic crust. Furthermore, we demonstrate that increasing the number of bipole sources is more effective in exploring anomalous bodies than increasing the number of receivers. Graphical abstract