Log Transmissivity Research Articles

Fortifying industrial cybersecurity: a novel industrial internet of things architecture enhanced by honeypot integration

The industrial internet of things (IIoT) has significantly transformed the industrial sectors by connecting devices, machines, and systems to enhance automation, efficiency, and decision-making. However, the increased interconnectivity also poses significant security challenges because IIoT devices control critical infrastructures and processes. Our work presents an implementation of a robust industrial cybersecurity strategy with a segmented network architecture, collaborative efforts between information technology (IT) and operational technology (OT) teams for enhanced resilience and effectiveness, and vertical honeypots across all Industry 4.0 levels integrated with Wazuh for log transmission and proactive threat response, alongside Snort intrusion detection system (IDS) monitoring network traffic. Additionally, we reinforce our architecture by Wazuh with Elasticsearch and Kibana as a security information and event management solution, facilitating data analysis and compliance enforcement through custom rulesets and cybersecurity threat intelligence (CTI) integration, with automatic updates for continuous adaptation against emerging threats.

Enhancing Syslog Message Security and Reliability over Unidirectional Fiber Optics

Standard log transmission protocols do not offer a robust way of segregating the log network from potential threats. A secure log transmission system and the realization of a data diode using affordable components are proposed. Unidirectional data flow prevents unauthorized access and eavesdropping, ensuring the integrity and confidentiality of sensitive log data. The system uses an encryption protocol that requires that the upstream and the downstream of the data diode are perfectly synchronized, mitigating replay attacks. It has been shown that message amplification can mitigate UDP packet loss, but this is only required when the data diode traffic is congested. The implementation of the encryption algorithm is suitable for resource-constrained devices and it has been shown to produce random-looking output even on a reduced number of rounds when compared to the parent cipher. Several improvements have been made to the original encryption algorithm for which an actual implementation was missing. Free software and datasets have been made available to reproduce the results. The complete solution is easy to reproduce in order to secure the segregation of a log network inside any scenario where logging is required by the law and log tampering must be prevented.

Increasing knowledge of the transmissivity field of a detrital aquifer by geostatistical merging of different sources of information

Transmissivity is a significant hydrogeological parameter that affects the reliability of groundwater flow and transport models. This study demonstrates the improvement in the estimated transmissivity field of an unconfined detritic aquifer that can be obtained by using geostatistical methods to combine three types of data: hard transmissivity data obtained from pumping tests, soft transmissivity data obtained from lithological information from boreholes, and water head data. The piezometric data can be related to transmissivity by solving the hydrogeology inverse problem, i.e., including the observed water head to determine the unknown model parameters (log transmissivities). The geostatistical combination of all the available information is achieved by using three different geostatistical methodologies: ordinary kriging, ordinary co-kriging and inverse problem universal co-kriging. In addition, there are eight methodological cases to be compared according to which log-transmissivity data are considered as the primary variable in co-kriging and whether two or three variables are used in inverse-problem universal co-kriging. The results are validated by using the performance statistics of the direct modelling of the unconfined groundwater flow and comparing observed water heads with the modelled ones. Although the results show that the two sets of log-transmissivity data are incompatible, the set of log-transmissivity data from the lithofacies provides a good log-transmissivity image that can be improved by inverse modelling. The map provided by inverse-problem universal co-kriging provides the best results. Using three variables, rather than two in the inverse problem, gives worse results because of the incompatibility of the log-transmissivity data sets.

Transcutaneous spinal stimulation in patients with intrathecal baclofen pump delivery system: A preliminary safety study.

To determine the effect of transcutaneous spinal stimulation (TSS) on an implanted intrathecal baclofen (ITB) pump in persons with traumatic spinal cord injury (SCI). Prospective clinical trial. Five individuals with chronic traumatic SCI, >18 years of age, and an anteriorly implanted Medtronic SynchroMed™ II ITB pump delivery system. Transcutaneous spinal stimulation trials with cathode at T11/12, with pump interrogation before, during and after stimulation. There was no evidence of any effect of the TSS in regards to disruption of the ITB pump delivery mechanism. Communication interference with the interrogator to the pump occurred often during stimulation for log transmission most likely secondary to the electromagnetic interference from the stimulation. One individual had elevated blood pressure at the end of the trial, suspected to be unrelated to the spinal stimulation. Based upon this pilot study, further TSS studies including persons with an implanted Medtronic SynchroMed™ II ITB pump can be considered when stimulating at the low thoracic spine, although communication with the programmer during the stimulation may be affected.

Impact of extractive industries on malaria prevalence in the Democratic Republic of the Congo: a population-based cross-sectional study

Extraction of natural resources through mining and logging activities provides revenue and employment across sub-Saharan Africa, a region with the highest burden of malaria globally. The extent to which mining and logging influence malaria transmission in Africa remains poorly understood. Here, we evaluate associations between mining, logging, and malaria in the high transmission setting of the Democratic Republic of the Congo using population-representative malaria survey results and geographic data for environmental features and mining and logging concessions. We find elevated malaria prevalence among individuals in rural areas exposed to mining; however, we also detect significant spatial confounding among locations. Upon correction, effect estimates for mining and logging shifted toward the null and we did not find sufficient evidence to detect an association with malaria. Our findings reveal a complex interplay between mining, logging, space, and malaria prevalence. While mining concessions alone may not drive the high prevalence, unobserved features of mining-exposed areas, such as human migration, changing vector populations, or parasite genetics, may instead be responsible.

Coupling Empirical Bayes and Akaike’s Bayesian Information Criterion to Estimate Aquifer Transmissivity Fields

In this work, an empirical Bayes method was applied to estimate highly parameterized transmissivity fields in 2D aquifers under conditions of steady flow. The Bayesian inverse procedure was coupled with the Akaike’s Bayesian information criterion to identify both the main transmissivity field and the hyperparameters of the prior distribution. The forward problem, solved with a version of MODFLOW, consists in computing hydraulic heads at monitoring points considering fully known boundary conditions, and the transmissivity field. As for the required observations for the inverse problem, the monitored hydraulic head data were used. Due to the nonlinear relationship between the observed data (hydraulic heads) and the unknowns (log transmissivity values in each finite difference cell), the inverse approach is based on a successive linearization method coupled with an adjoint state methodology. At the end, the posterior distribution of the unknowns allows quantifying their uncertainty. The methodology was tested on a well-known literature case study consisting of a confined aquifer, with both Dirichelet- and Neumann-type boundary conditions and considering different degrees of heterogeneities. The inverse approach showed robust, efficient results fully consistent with other methods available in the literature. The methodology was implemented in a free and user-friendly code named ebaPEST.

Design of the equaliser with lower-order Chebyshev polynomial for bandwidth expansion of transmission channel of logging cable

ABSTRACTThis paper introduces the logging cable equaliser. In logging engineering, the seven-core cable has been widely used as transmission medium, which has a narrower effective bandwidth. In order to improve the data transfer rate, it is necessary to expand the effective bandwidth. We have proposed a design method of equaliser based on Chebyshev polynomial in this paper. This scheme could compensate the high-order channel attenuation and expand the effective width with lower-order Chebyshev polynomials. The equaliser could also compensate the phase shift of the transfer data which is caused by the non-linear characteristic of logging cable. We have also simulated the scheme with Matlab and produced the circuit board to demonstrate the practical application effect. It is proved that for the non-linear logging transmission channel, the proposed scheme has a good effect on the expansion of the effective bandwidth. It could provide enough bandwidth to enhance the data transmission rate.

СРАВНИТЕЛЬНЫЙ АНАЛИЗ РЕЗУЛЬТАТОВ СИЛОВОГО ВОЗДЕЙСТВИЯ НА ЖЕЛЕЗНОДОРОЖНЫЙ ПУТЬ С ПРИМЕНЕНИЕМ МЕТОДОВ ШЛЮМПФА, «РЖД-2016» И «НВЦ-ТКП»

Objective: To improve the integrity of running and dynamic testing results of force impact on the track, on the basis of modern facilities of data logging and wireless transmission from rotary elements of a car, as well as the change from indirect to direct methods of measurement. Methods: Comparative running and dynamic tests of the impact on the track were held simultaneously on the same section of the track, using three methods of logging vertical and side forces, that is Schlumpf (State Standard R 55050-2012), “RZhD-2016” and “NVTs-TKP” methods. The key difference of the third method was the application of strain-gauge set of wheels (TKP), making it possible to keep a continuous record of forces acting in the “wheel-rail” system throughout the track, whereas other methods allowed for the realization of the above mentioned only on districts with a limited amount of sections. Results: According to the results of comparative testing, a conclusion was made on the improvement of integrity and justification of the method of “NVTs-TKP” with an application of strain-gauge set of wheels. Practical importance: It was suggested to apply “NVTs-TKP” method to implementing organizations of running and dynamic tests when evaluating the load of an innovative rolling stock on the track.

Arctic Anthropogenic Sound Contributions from Seismic Surveys during Summer 2013

Statoil deployed three acoustic recorders from fall 2013 to fall 2014 in the Arctic region as part of a broad scientific campaign. One recorder was installed in the Barentsz Sea south-east of Spitsbergen. Two other recorders were installed in the Greenland Sea north-east of Greenland. All recorders were operating at a duty cycle of 2 minutes on and 30 minutes off, sampling at 39062 Hz and recording in 24 bits. The Greenland recorders both captured air gun surveys performed during the summer months of 2013, allowing to estimate the transmission loss in the Arctic over long ranges. This paper presents log(R) transmission loss curves for these scenarios that can help assessing the acoustic shipping impact for future expeditions.

Factors controlling the permeability distribution in fault vein zones surrounding granitic intrusions (Ore Mountains/Germany)

AbstractAn outstanding legacy data set has been compiled from underground excavations mostly prospected and mined by the former Soviet (German) Stock Company Wismut describing the hydrology of faulted basement rocks in the Ore Mountains (SE Germany). It consists of more than 5000 detailed descriptions of groundwater inflows to about 660 km of tunnels and 57 km of drillings measured during or shortly after excavation. Inflow measurements (recorded between 1E−8 and 4E−2 m3/s) have been converted to fracture transmissivities using a simplified analytical solution. Discarding site specific effects, the median log transmissivity decreases from 1E−7 to 1E−10 m2/s within the studied depth interval of 0–2000 meters below ground surface (mbgs), and the spacing of conductive fracture increases from 0.1 to 2500 m. This general trend is overprinted at three mining sites by a clear reversal of fracture transmissivity which correlates with contact metamorphic aureoles around Variscan granite intrusions (327–295 Ma). We hypothesize that this transmissivity increase is caused by processes accompanying granite intrusion and contact metamorphism. The thickness of these hydraulically active aureoles is greater in lower‐grade metamorphic schist than in higher‐grade metamorphic gneisses. Rock mass equivalent continuum conductivities have been estimated by arithmetic averaging of fracture and matrix transmissivities over 100 m intervals and have been converted to permeabilities. The median equivalent continuum permeability decreases with depth according to log(k) = − 1.7 * log(z) − 17.3 (k in m2 and increasing depth z in kilometer being positive). Matrix conductivity controls the bulk conductivity below about 1000 mbgs and is less sensitive to the occurrence of contact metamorphic aureoles.

EnKF coupled with groundwater flow moment equations applied to Lauswiesen aquifer, Germany

Summary We describe a field application of a new data assimilation method recently proposed by Panzeri et al. (2013, 2014). The method couples a modified Ensemble Kalman Filter (EnKF) algorithm with stochastic moment equations (MEs) governing space–time variations of (theoretical ensemble) mean and covariance values of groundwater flow state variables (hydraulic heads and fluxes). Whereas traditional EnKF entails Monte Carlo (MC) simulations and suffers from inbreeding, our approach obviates both. Synthetic case studies have shown the ME-based approach to be computationally efficient and accurate when compared to MC-based results. Here we use our ME-based method to assimilate drawdown data recorded during cross-hole pumping tests in the heterogeneous alluvial Lauswiesen aquifer near Tubingen, Germany. Our results include an estimate of log transmissivity distribution throughout the aquifer and corresponding measures of estimation error. We validate our calibrated model by using it to predict drawdowns recorded during another pumping test at the site and compare its performance with that of standard MC-based EnKF.

Log Secure Access and Transmission Technology Research in a Virtual Environment

This paper puts forward a logging process monitoring method based on full virtualization to solve the problems of log lost and non security log transmission. Making use of fully virtualized technology, this method detects the suspicious log in the virtual monitor machine and makes record of logs. It used SSL technology to transmit log to the remote backup machine to save and analyze it.

Effects of electric-acoustic and acoustic-electric conversions of transducers on acoustic logging signal

Based on an acoustic logging transmission network and the engineering pattern of a sliding wave in acoustic logging, analysis and calculations have been performed in a study of the effects of the electric-acoustic and acoustic-electric conversions of the transducers on the acoustic logging signal. The results show that acoustic-electric conversion through the transducer can cause not only a serious disturbance in the signal amplitude, but also an apparent transmission delay. For engineering applications, the amplitude variation and transmission delay must be accounted for in a practical analysis of the acoustic logging signal in rocks. The results also show that with enhanced understanding and proper justification, the error caused by the acoustic-electric conversion can be significantly reduced in evaluation of the cement bond quality of a cased well, and the accuracy of rock porosity calculated using the measured acoustic velocity can be increased.

Interaction between nk cells and HLA-G1 at the placental interface of HIV-1 infected pregnant women: additional risk factors or physiological association?

Background: Human Leucocyte Antigen-G (HLA-G) molecules are involved in the inhibition of cell-mediated immune responses and could promote the propagation of HIV-1 infection across the placental interface thus increasing the risk of vertical transmission. Therefore, the objective of this study was to assess whether the Major Histocompatibility Complex (MHC) - coded molecule HLA-Ginhibits Natural Killer (NK) cell activity thereby, assisting viral penetration across the placental barrier in HIV-1 positive pregnant women. Study Design & Methods: Natural Killer (CD56+) cell activity and placental HLA-G1 expression was assessed using immunohistochemistry and real-time polymerase chain reaction (RT-PCR) techniques, respectively. Studies were performed on a total of fifty five placental samples obtained from HIV-1 infected mothers at birth. Results: Low numbers of NK cells increased risk of vertical transmission [OR = 3.424 (95%CI 0.65-17.89)]. The risk of babies becoming infected increased by 1.3 with every 1 unit increase in HLA-G1 expression. A positive correlation was observed between mothers’ log viral load and transmission of infection to the baby (p = 0.047; 95%CI 1.029-11.499). Conclusion: Low NK cell activity at the placental interface increased the risk of vertical transmission. Maternal viral load remained a strong predictor of viral transmission.

Two-dimensional stochastic analysis of flow in leaky confined aquifers subject to spatial and periodic leakage

This paper addresses the issue of flow in heterogeneous leaky confined aquifers subject to leakage. The leakage into the confined aquifer is driven by spatial and periodic fluctuations of water table in an overlying phreatic aquifer. The introduction of leakage leads to non-uniformity in the mean head gradient and results in nonstationarity in hydraulic head and velocity fields. Therefore, a nonstationary spectral approach based on Fourier–Stieltjes representations for the perturbed quantities is adopted to account for the spatial variability of nonstationary head fields. Closed-form expressions for the variances of hydraulic head and specific discharge are developed in terms of statistical properties of hydraulic parameters. The results indicate that the spatiotemporal variations in leakage leads to enhanced variability of the hydraulic head and of the specific discharge, which increase with distance from any arbitrary reference point. The coefficient of leakage and the spatial structure of log transmissivity field and of the amplitude of water table fluctuation are critical in quantifying the variability of the hydraulic head and of the specific discharge.

Using the nonstationary spectral method to analyze asymptotic macrodispersion in uniformly recharged heterogeneous aquifers

This paper describes an investigation of the influence of uniformly distributed groundwater recharge on asymptotic macrodispersion in two-dimensional heterogeneous media. This is performed using a nonstationary spectral approach [Li, S.-G., McLaughlin, D., 1991. A nonstationary spectral method for solving stochastic groundwater problems: unconditional analysis. Water Resour. Res. 27 (7), 1589–1605; Li, S.-G., McLaughlin, D., 1995. Using the nonstationary spectral method to analyze flow through heterogeneous trending media. Water Resour. Res. 31 (3), 541–551] based on Fourier–Stieltjes representations for the perturbed quantities. To solve the problem analytically, focus is placed on the case where the local longitudinal dispersivity α L is much smaller than the integral scale of log transmissivity λ (i.e., α L / λ ≪ 1). The closed-form expressions are obtained for describing the spectrum of flow velocity, the variability of flow velocity and asymptotic macrodispersion, in terms of the statistical properties and the integral scale of log transmissivity, local transport parameters and a parameter β [Rubin, Y., Bellin, A., 1994. The effects of recharge on flow nonuniformity and macrodispersion. Water Resour. Res. 30 (4), 939–948] used to characterize the degree of flow nonuniformity due to the groundwater recharge. The impact of β on these results is examined.

Type curve interpretation of late‐time pumping test data in randomly heterogeneous aquifers

The properties of heterogeneous media vary spatially in a manner that can seldom be described with certainty. It may, however, be possible to describe the spatial variability of these properties in terms of geostatistical parameters such as mean, integral (spatial correlation) scale, and variance. Neuman et al. (2004) proposed a graphical method to estimate the geostatistical parameters of (natural) log transmissivity on the basis of quasi–steady state head data when a randomly heterogeneous confined aquifer is pumped at a constant rate from a fully penetrating well. They conjectured that a quasi–steady state, during which heads vary in space‐time while gradients vary only in space, develops in a statistically homogeneous and horizontally isotropic aquifer as it does in a uniform aquifer. We confirm their conjecture numerically for Gaussian log transmissivities, show that time‐drawdown data from randomly heterogeneous aquifers are difficult to interpret graphically, and demonstrate that quasi–steady state distance‐drawdown data are amenable to such interpretation by the type curve method of Neuman et al. The method yields acceptable estimates of statistical log transmissivity parameters for fields having either an exponential or a Gaussian spatial correlation function. These estimates are more robust than those obtained using the graphical time‐drawdown method of Copty and Findikakis (2003, 2004a). We apply the method of Neuman et al. (2004) simultaneously to data from a sequence of pumping tests conducted in four wells in an aquifer near Tübingen, Germany, and compare our transmissivity estimate with estimates obtained from 312 flowmeter measurements of hydraulic conductivity in these and eight additional wells at the site. We find that (1) four wells are enough to provide reasonable estimates of lead log transmissivity statistics for the Tübingen site using this method, and (2) the time‐drawdown method of Cooper and Jacob (1946) underestimates the geometric mean transmissivity at the site by 30–40%.

Transmissivity upscaling in numerical models of steady aquifer flow: Conditional statistics

Numerical solution of regional scale aquifer flow requires discretizing the transmissivity T. For spatially varying T and by the stochastic approach, T is modeled as a random field. Typically, both the numerical element scale R and the log transmissivity integral scale I are of order of hundreds to thousands meters. Consequently, the upscaled block transmissivity is random and its statistical moments depend on those of the fine scale T, on flow conditions, and on R/I. Modeling Y = ln T as a two‐dimensional normally distributed stationary random field, we have derived [Dagan and Lessoff, Water Resources Research, 43, W05431, doi:10.1029/2006WR005235 2007] the unconditional statistics of the upscaled = ln , accurate to the first‐order in σY2, the log transmissivity variance. Both cases of mean uniform flow [solved previously by Indelman and Dagan, Transport in Porous Media, 12, 161‐183, 1993] and of strongly nonuniform flow in a circular block of radius R centered at a well of radius rw, were considered. Such upscaling applies either to elements in regions of natural gradient flow or those surrounding a projected well, respectively, which are sufficiently far from points of measurement of T. The present article extends the analysis to account for the presence of a measurement removed in the center of the element (e.g., result of a pumping test). The fine scale conditional log transmissivity Yc is modeled as multi‐Gaussian, of nonstationary mean and of two point covariance which depend on the measured value and distance from the measurement location. Upscaling in mean uniform flow is related, for instance, to the case of a pumping well which is not operative, but served to determine T while natural gradient flow conditions prevail in the area. It was found that upscaling has a significant effect upon the mean upscaled log transmissivity that changes from the measured value for R/I ≪ 1 to the effective one 〈Y〉 = ln TG for R/I > 6. Similarly, the conditional log transmissivity variance is greatly reduced compared to the unconditional case. It tends to zero for R/I → 0 or R/I → ∞, and it reaches a maximal value of around 0.15 σY2 for R/I ≃ 1. The second case, of upscaling in well flow, applies to an element with an operative well at its center, which was used to determine the transmissivity Tw. Unlike mean uniform flow, it is found that upscaling has a very small effect for the realistic values of rw/I = 0(10−3) and R/I < 5. In this case the upscaled transmissivity is practically deterministic and equal to the given Tw. A summary of the two articles, (Dagan and Lessoff, 2007) and the present one concludes the paper.

Fracture and bedding plane control on groundwater flow in a chalk aquitard

Shallow groundwater in the northern Negev desert of Israel flows preferentially through a complex system of discontinuities. These discontinuities intersect what would otherwise be a massive, low-conductivity, high-porosity Eocene chalk. Vertical fractures and horizontal bedding planes were observed and mapped along approximately 1,200 m of scanline, 600 m of core and 30 two-dimensional trace planes. A bimodal distribution of size exists for the vertical fractures which occur as both single-layer fractures and multi-layer fractures. A bimodal distribution of log transmissivity was observed from slug tests conducted in packed-off, vertical intervals within the saturated zone. The different flow characteristics between the horizontal bedding planes and vertical-type fractures appear to be the cause of the bimodality. Two distinct conceptual models (discrete fracture network) were developed based on the fracture orientation, size, intensity and transmissivity statistics derived from field data. A correlation between fracture size and hydraulic aperture was established as the basis for calibrating the simulated model transmissivity to the field observations. This method of defining transmissivity statistically based on prior information is shown to be a reasonable and workable alternative to the usual conjecture approach towards defining transmissivity in a fractured-rock environment.

Equivalent transmissivity of heterogeneous leaky aquifers for steady state radial flow

The purpose of this study is to estimate the equivalent transmissivity for two‐dimensional steady state radial flow toward a fully penetrating well in a heterogeneous leaky aquifer. The log transmissivity of the pumped aquifer is modeled as a multivariate random spatial function with stationary mean and exponential semivariogram, while the aquitard conductance is assumed to be spatially uniform. An approximate expression for the upscaled or block transmissivity, defined as the transmissivity of an equivalent homogeneous leaky aquifer system with the same pumping, is proposed. The proposed relation expresses the upscaled transmissivity as a weighted average of the log transforms of the point transmissivity values. Monte Carlo simulations are used to numerically validate the proposed upscaling expression for wide ranges of aquifer parameters. The relation of the weighing function to the statistical parameters of the transmissivity field is discussed. The first and second moments of the upscaled transmissivity are also estimated as a function of the problem parameters. The expected value of the equivalent transmissivity is shown to increase from the geometric mean to the arithmetic mean as the aquitard conductance increases from zero to infinity.