Location Of Observation Point Research Articles

Development of a System for Monitoring the State and Pollution of Land Surface Water in the Design Area of the Nizhneboguchanskaya HPP

On the Angara River, there is already a cascade of four hydroelectric power plants. It is planned to build a new dam above Boguchany — Nizhneboguchanskaya hydroelectric station. This creates an additional burden on the river ecosystem. To record the initial state of the Angara River and track the dynamics of indicators, a program for monitoring the state and pollution of land surface waters in the design area of the Nizhneboguchanskaya hydroelectric power station was developed. The location of observation points was determined by taking into account the existing network of state monitoring of the investigated area of the Angara River and the analysis of the sources of anthropogenic pollution of the investigated area of the Angara River. It was proposed to make adjustments to the existing state monitoring system. It is necessary to add new observation points, expand the range of hydrochemical components and add hydrobiological studies. It is planned to establish 12 observation points and 16 sites. Sampling frequency — up to seven times a year in characteristic phases of hydrological regime. Hydrological studies should be carried out during the growing season (June — September).

The scattering of seismic waves from saturated river valley with water layer: Modelled by indirect boundary element method

River valley topography will cause local amplification effect and significant spatial variation effect of ground motion. In this paper, an indirect boundary element method (IBEM) is proposed to solve seismic wave scattering in sedimentary valleys. A ``water layer - soft sedimentary layer - poroelastic halfspace'' model is established, and the effects of water layer, soil parameters of sedimentary layer and terrain on incident P and SV waves are discussed in detail. The numerical results demonstrate that the scattering characteristics are closely related to the depth of water layer, porosity, the location of observation points, et al. The surface displacement amplitude decreases with increasing water layer thickness, with a maximum reduction of 16.2%. Moreover, the peak ground acceleration (PGA) is significantly larger and the seismic response is stronger when the observation point is located outside the valley compared to the observation point inside the valley. The influence of porosity on Fourier spectrum and response spectrum curve is mainly reflected in the peak value and predominant frequency. The research results can provide a theoretical basis for the seismic fortification of the structures around the saturated sedimentary valley.

Object-Based Learning Rocks! Integrating Digital Solutions into Geology Practicum

Over several years, the authors have pursued technology solutions to the difficult arena of moving geology practicum work into the online space (e.g., Tetley and Daczko, 2014). Through a partnership of teaching academics with professional staff trained in digitisation and software development, the authors have now solved the problem of verisimilitude and utility and opened a raft of future opportunities including a smooth and seamless transition to online teaching when presented with recent pandemic lockdowns. “Teaching geology with digital tools advances students’ learning experience by providing access to high-quality outcrops, enhancing visualization of 3D geological structures and improving data integration.” (Senger et al., 2021) Our solution required innovation on several fronts. Firstly, 3D digitisation and gigapixel imaging processes and methods were tried, evaluated, abandoned and refined until an ideal solution was developed that could actually replace the physical rock hand samples. Secondly, software platform development and integration was required. We utilised a custom developed 3D platform (Pedestal 3D) and also developed a bespoke platform for virtual petrographic microscopy (ImageMatrix). Finally, as “the organisation, logistics and relevance of an OBL session is critical to its efficacy” (Chatterjee and Hannan, 2016), all of this needed significant pedagogical underpinning and integration to ensure learning and outcomes were not impacted by the technology shift. We found that generally, digital resources allow for and encourage much more practice of the professional skills required for identification of minerals. “Most professional geoscientists spend much of their day in front of work-stations, interpreting or modelling digital data, in two or three dimensions.” (Bond and Wightman, 2012) so this mode of delivery is a naturally suited authentic task. On top of that, digital pre-lab work prepares students for being confronted with actual samples. Being able to digitally annotate the samples allowed for a virtual “guide on the side” pedagogy to allow for clarity of tasks and identification of specific object traits that are difficult in the traditional practical setting. The three main areas of impact were in Workshops, Field Trips and general Practicum. The specific mineral identification workshops were extended in a blended sense pre-COVID-19 and then seamlessly moved to online when required during the pandemic without any further development. Geological fieldwork traditionally has several core functions. “These include the determination of the geographical location of observation points, the description of outcrops, the macroscopic description of rocks, the detection of lithological boundaries, the spatial fixation of planar and linear objects (folds, joints, faults, linear position of minerals, etc.).” (Bubaniak et al., 2020) To respond to this digitally, a landmark yearly field trip in the program was developed into a fully online virtual field trip. The general practicum across the course was enabled to be taught in an online only mode which had never been possible before. We found that grade distribution did not suffer during the COVID-19 period which demonstrates that this mode of Digital Object-Based Learning is as good as traditional approaches to teaching. Although not originally intended, coursework could now also be offered fully online which opens a range of possibilities moving forward.

RESULTS OF THE TECTONOPHYSICAL STUDY IN THE DZHANKHOT THRUST ZONE (NORTHWESTERN CAUCASUS)

The paper presents the results of detailed structural analysis of the Dzhankhot thrust zone which is a part of the system of overthrust nappe structures in the southern slope of the Northwestern Caucasus. The relevance of the research topic is found on the reason that despite the obvious importance of these overthrust nappes in the structure of the Greater Caucasus there is still lack of in-situ observational data on the detailed structure of thrust zones and on tectonic stress distribution pattern therein.As a result of the structural and geological studies of small disjunctive and plicative forms in the Upper Cretaceous and Paleocene sediment contact along the Dzhankhot thrust, there were identified the major structural and tectonic deformation patterns and the areal distribution of tectonic deformations depending on the distance to the thrust. There was determined the major type of stress in different parts of the thrust zone. There was shown the difference in the development of geological indicators of faults for different elements of the folded structures. In some cases, there was determined the sequence of deformations, from synsedimentary structures (clastic dikes in particular) to post-sedimentary brittle structures.The orientation of principal stress axes determined from the reconstruction data by method of cataclastic analysis of faults confirms a thrust-type deformation within the studied area near the Dzhankhot thrust. Local stress-tensor determinations are in good agreement with the location of observation points in the regional tectonic structure. Trajectories of the maximum compression axes, most of which are submeridionally and NNW-trending, change orientation to the northwest in the immediate vicinity of the Dzhankhot thrust fault zone. The identified features of tectonic structure and stressed-strained state of the Dzhankhot thrust zone allow considering this area as a natural structural and tectonophysical testing ground for both tectonic-stress-reconstruction-improvement methodologies and a study on natural deformation structures of the Greater Caucasus.

A new analytical model for ballistic waves generated by subsonic penetration in water

A meticulous analytical investigation was conducted to better comprehend the characteristics of ballistic waves generated by subsonic penetration in water. In this study, a new analytical model was developed, in which a more reasonable distribution of source strength was considered. Ballistic experiments for a spherical projectile penetrating in a square tube were conducted to verify the new model, and better agreements were obtained between the experimental results and those predicted by using this new analytical model. Moreover, effects of projectile density, initial projectile velocity, and location of observation point on the characteristics of ballistic waves were systematically explored. Parameter studies reveal that the value of first pressure peak of ballistic waves varies linearly with v02, and is close to a limit constant with the increase of projectile density. The amplitude of ballistic waves decreases with the increase of depth of observation point due to projectile deceleration, and the second pressure peak of ballistic waves disappears when the observation point is far away from the trajectory. The present analytical model can more accurately evaluate the pressure loads in hydrodynamic Ram due to subsonic penetration, and provide a significant guiding reference for precise design of fluid-filled defense structures.

Geoelectric studies of the Kozloduy nuclear power plant region, Bulgaria

The task of the work was geoelectrical studies using variations of the magnetotelluric (MT) field of the Kozloduy nuclear power plant (KNPP) region and the integration of its results with other geological and geophysical knowledge. This paper presents the determined interpretation parameters of the MT field. The KNPP is located on the right bank of the Danube River in close proximity to the river. This fact, together with the location of electrified railways determined the unique network of locations of observation points for MT field variations. Based on the analysis of Earthquake Catalogs of Bulgaria and international seismicity databases, a map of the seismicity of nuclear power plant areas was built. Over the past 50 years, about 750 earthquakes (mainly south of KNPP) have been recorded at a distance of 40—80 km from the KNPP. Two magnetotelluric stations GEOMAG-02 were used at measurement sites, but equipment for recording electrical channels was available only for one station (due to the lack of another set of non-polarizable electrodes). The MT field variations were observed at 21 points, which are located on the territory with sides approximately 30—35 km from east to west and 40—50 km from north to south. For all observation points on the profile, only the parameters of the vertical magnetic transfer function (VMPF) were determined, in the form of the real (Cu) and imaginary (Cv) parts of the induction vector. The steadily induction vector was defined for periods from 10—20 to 4900—10 800 s. For most points it was possible to estimate the values Cu, Cv with an error of 0.02—0.04 and AzCu, AzCv 3—5°. The analysis showed the presence of anomalous behavior of Cu, Cv in different intervals of periods at some points. In the shortest (about 20 s) and longest periods (600 to 1000 s), the Cu directions completely coincide and indicate the presence of anomalous conductivity of the quasi-longitudinal strike to the west of the study area. This behavior of the Cu vector is in good agreement with power isohypsum strike of the Cenozoic deposits. At intermediate periods of 50—200 s, the behavior of Cu is more complex. Approaching the zone of high seismicity, the direction of the Cu differs from the previous ones by almost 90°. On the Geoelectrical sections, obtained as a result of 1D inversions of MTS curves at 4 points located in the southern part of the region, anomalous layers are identified (ρ about 10 ohm · m, the depth of the center of the object is 15—20 km). It can be assumed that well-conducting objects in the Earth’s crust of the region, apparently, prevent the propagation of seismic waves from nearby earthquakes to the north towards the KNPP.

A comprehensive approachfor off-road trafficability evaluation and development of modified equation for estimation of RCI to assessregional soil variation using geospatial technology

The information of terrain is highly valuable as the accuracy of decision maker depends on input data for taking the correct decision. For planning of any successful off-road movement, the terrain information plays the vital role. This paper describes the state of art of off-road trafficability leading from the contributing factors, Instruments for measurements and trafficability mapping techniques in chronological order. In modern times, the number & type of tracked or wheeled vehicles, has increased many times, therefore off-road trafficability for operation planning became a complex task to handle. The accuracy and reliability of measurements involved in trafficability will play a major role for any successful operation. Off-road trafficability shows the capacity of soil required for vehicular movement. Remolding Cone Index (RCI) indicates the soil's capability for off-road movement. In this study, the area was divided in equal small grids for ease of computation of RCI. Geospatial technology provides the platform to determine the locations of observation points as well as the extrapolation of information of inaccessible area using geospatial tools and techniques. RCI values were computed for each grid and also measured with cone penetrometer in the field. R2 value for observation values was determined for different soils present in the area to check the accuracy of measurements and then based on observed value and computed value, R squared (coefficient of determination) values (0.7754 and 0.4867) were evaluated for both study areas to get the idea about relevance, reliability and accuracy. Residual RCI (RRCI), difference of computed & observed was also analyzed for different soils for different moisture conditions. Based on thisanalysis, a modified equation was developed for different type of soils present in the study area. This development will pave the way to compute the RCI accurately, which will be used to assess the off-road trafficability of other areas in similar manner. Therefore, this study is useful to assess the regional variation of soil behavior towards trafficability based on modified equation.

Segmentation of Marine Forecast Zone in Korea by Using Wave Data: Based on K-Means Clustering Algorithm

Kim, M.-S.; Kim, D.; Eom, H.; You, S.H.; Jeong, J.-S., and Woo, S.-B., 2021. Segmentation of marine forecast zone in Korea by using wave data: Based on k-means clustering algorithm. In: Lee, J.L.; Suh, K.-S.; Lee, B.; Shin, S., and Lee, J. (eds.), Crisis and Integrated Management for Coastal and Marine Safety. Journal of Coastal Research, Special Issue No. 114, pp. 251–255. Coconut Creek (Florida), ISSN 0749-0208. The Korea Meteorological Administration (KMA) classified the forecast zone based on the administrative districts, weather characteristics, civil complaints, and location of observation points. A cluster analysis was performed using the wave observation and model data to check the validity of the current forecast zone for the wave forecast. The cluster analysis is a method used to group areas with common characteristics. In this study, a set of n objects was decomposed into k clusters (groups) and a distance-based method, k-means clustering algorithm, was used. As the data structure of the cluster analysis, the mean and standard deviation of the significant wave height and wave period during the period of 2014 to 2016 were selected. When performing the cluster analysis with wave heights and wave periods observed at ocean buoys, 11–12 cluster conditions have relatively significant internal evaluation indices suggesting the distance and variance ratio between points and points within each cluster or between distinct clusters. However, since there were few points to perform the segmentation of the marine forecast zone using only the observation data, there was a problem that clusters concentrated in a specific area were distributed. Therefore, it is necessary to perform the cluster analysis by using the KMA wave model for the segmentation of the marine forecast zone. As a result, 10 cluster condition showed the best internal evaluation indices. Although the results of the cluster analysis did not differ significantly from the current forecast zone, the segmentation was made more distinct and detailed.

Analysis of beampattern dwell time for planar frequency diverse array

Frequency diverse array (FDA) has received much attention due to its both range–angle-dependent beampattern. However, most of the existing works focus on the linear FDA, and time-varying characteristics of its beampattern only give a rough qualitative analysis. To further study the spatial beampattern dwell time issues, the pulsed-planar FDA measurement model is first given, and then, the quantitative analysis of beam dwell time which can be affected by observation point location (azimuth, elevation, and range) and array antenna frequency offset coding method for a given pulse transmitting signal is presented. Finally, the theoretical analysis is proved to be consistent with the simulations.

Domain of Influence Analysis: Implications for Data Assimilation in Space Weather Forecasting

Solar activity, ranging from the background solar wind to energetic coronal mass ejections (CMEs), is the main driver of the conditions in the interplanetary space and in the terrestrial space environment, known as space weather. A better understanding of the Sun-Earth connection carries enormous potential to mitigate negative space weather effects with economic and social benefits. Effective space weather forecasting relies on data and models. In this paper, we discuss some of the most used space weather models, and propose suitable locations for data gathering with space weather purposes. We report on the application of Representer analysis (RA) and Domain of Influence (DOI) analysis to three models simulating different stages of the Sun-Earth connection: the OpenGGCM and Tsyganenko models, focusing on solar wind - magnetosphere interaction, and the PLUTO model, used to simulate CME propagation in interplanetary space. Our analysis is promising for space weather purposes for several reasons. First, we obtain quantitative information about the most useful locations of observation points, such as solar wind monitors. For example, we find that the absolute values of the DOI are extremely low in the magnetospheric plasma sheet. Since knowledge of that particular sub-system is crucial for space weather, enhanced monitoring of the region would be most beneficial. Second, we are able to better characterize the models. Although the current analysis focuses on spatial rather than temporal correlations, we find that time-independent models are less useful for Data Assimilation activities than time-dependent models. Third, we take the first steps towards the ambitious goal of identifying the most relevant heliospheric parameters for modelling CME propagation in the heliosphere, their arrival time, and their geoeffectiveness at Earth.

On near- and far-field acoustic radiation characteristics of ships in finite-depth water environment

A simplified calculation model is established to evaluate the acoustic radiation of the single-shell underwater ship structure considering typical ship mechanical excitation. The three-dimensional sono-elastic method of ships in Pekeris ocean-acoustic waveguide environment is used to calculate the acoustic radiation of the ship structure in three water environments. Variation of the ship's acoustic radiation, from the near field to the far field, is analyzed. In the near field, the value of the radiated acoustic pressure varies greatly with the changing of spatial coordinates (near-field acoustic waves exist). When evaluating underwater acoustic radiation of the ship quantitatively in the engineering, the locations of observation points (where the radiated noise is measured under water) are usually close to the ship. The distance of the observation point away from the hull is even smaller than the length of the ship taking into account the requirement of a sufficient SNR (Signal-to-Noise Ratio). At such a distance, it cannot guarantee that the converted acoustic source levels are basically stable and can effectively reflect the acoustic radiation magnitude in the far-field, that is, the condition of far-field investigation is not satisfied. This study will be helpful in answering two issues of concern in engineering: (1) How much near-field acoustic disturbance will be introduced if the distance from the hull to the observation point is less than the length of the ship? (2) How far does the observation point need to be away from the hull in order to exclude the near-field acoustic disturbance effectively?

Modeling total crime and the affecting factors in Central Java using geographically weighted regression

Analysing the relationship between number of crime cases and affecting factors became an interesting research topic over the last ten years. The total number of crime in Indonesia did not show a consistent decrease. In order to upgrade people safeness quality, the government need to know the factors influence people committing crime acts. Rather than using classical regression analysis, geographically weighted regression (GWR) was preferable since it gave a better representative model by effectively resolve spatial non-stationary problem which is generally exist in spatial data of social phenomenon. Spatial non-stationary is a situation when the relationship between variables are significantly different in each location of observation point, so that classic regression analysis will result a misleading interpretation in some location. GWR handled the spatial non-stationary problem by generating a single model in each observation point which allow different relationship to exist at different point in space. This study used number of crime cases (y) as the dependent variable and the factors which affect the number of crime cases as independent variables that consist of the number of illiterates (X1), the number of unemployed (X2), the number of poor population (X3), population density (X4), the number of victims of drug (X5). This study used secondary data collected by POLRI, BPS and Indonesian Ministry of Social Affairs in Central Java during 2015. GWR generated model for 35 city/regency in Central Java.

THE METHOD OF EFFICIENT DISTRIBUTION OF DIFFERENT ELEMENTS OF A COMPLEX SYSTEM OF CONTROL

Context. An important prerequisite for reliable protection of the state border of Ukraine is the effective detection of violators of the border. For this purpose, various state-of-the-art systems and observation complexes are used at the border agency, and some border dresses are equipped with the latest technical means of border guarding. The diversity of possibilities of individual means of observation in their complex use makes it important to determine the effective location of observation points, taking into account the features of the terrain. Objective. The purpose of the work is to develop a method for effective placement of elements of complex surveillance systems of the border agency. Method. The work proposes a heuristic approach to solving the problem of determining the effective placement of different capabilities of technical means of observation. The developed method is based on the cyclic use of the known method of combinatorial optimization of placement of observation points for all components of a complex surveillance system of the border agency with adjustment after each iteration of the overburden. At the same time, with the use of geo-processing takes into account the barrier to the negative impact of terrain and the possibility of different technical means of surveillance in different conditions. To assess the effectiveness of the functioning of the components of the surveillance system, an indicator is used reflecting the share of the area of the strip of overlap, which provides the identification of objectives. Results. As a result of using the proposed methodology, a rational structural construction of a complex surveillance system of the border guard body and a set of uncontrolled points of the area are obtained. This plurality can be used in planning the service of the units of the border guard. The description of algorithmic and program realization of the proposed method is given. Using the developed software, the optimization of the placement of three types of elements of a complex observation system (towers of the system of optoelectronic observation, mobile thermal imaging complexes, observation posts) was carried out. Conclusions. Modern construction of complex surveillance systems of the border agency in many cases is not optimal. To increase the efficiency of their operation, it is possible to use the proposed method of placement of elements of these systems on the ground.

Mathematical Model for Errors Estimation of Object’s Location Parameters Determination Using Flying Platform

Some tasks require identification of landmarks in districts beyond the reach of existing optical observation facilities. The accuracy of their determination significantly affects the effectiveness of the use necessary equipment during the task. In the paper an algorithm to determine the object parameters using a flying platform is offered. An observation point is installed which is equipped with a navigation system to solve this task. This ensures its orientation and positioning. From the observation point an aerial observation point is displayed. It is suggested to use a flying platform. The coordinates of the flying platform are determined relative to the observation point, the coordinates of the landmarks are determined relative to the flying platform. The mathematical model of the estimation error determination of object coordinates with the help of a flying platform is proposed. The analysis of errors in determining the parameters of the object using a flying platform is conducted. Analysis of the results of mathematical modeling is conducted using the package of applications Mathcad. The dependence of these parameters on the relative position of the observation point, platforms and object is examined. It is shown that the main contribution to the error of determining the coordinates of the landmark is given by the errors of determining the observation point location and measuring the range. An analytical correlation is obtained, which allows to estimate the errors of determining the coordinates of the landmark using the flying platform with known errors in determining the observation point coordinates and the range determination of the range finder.

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The most important features of the drone (unmanned aerial vehicle) are its survivability, noise immunity and secrecy. In this context, the threats that arise during the protection of weapons depots and important public facilities have been analyzed. The parameters of the early detection of drone attacks have been studied. The possibilities of countering the unmanned aircraft attack by means of air defense and electronic warfare systems are considered. In the geographic information system for an electronic map of the area, a simulation model is proposed. The model has an aircraft route organizer that allows analyzing possible flight directions at given altitudes and speeds on various route segments. With fixed initial conditions and repeated model execution, a statistically significant result can be obtained in the form of a mathematical probability of defeat (neutralization) of an unmanned aerial vehicle. This feature is implemented using the definition in the model of the states and events of an unmanned aerial vehicle along segments of the route. For example, a case when the device enters the zone of action of one or more air defense means. Or, an example of another situation, when the drone with a certain probability is affected by air defense units. In the model it is possible to calculate and correct the probabilities of detection, neutralization and hitting of the drones. If in the process of the simulation model re-running, negative results in covering the objects are obtained, then the locations of observation points, electronic warfare and anti-aircraft defense facilities should be changed. The newly formed detection, cover and defeat zones should ensure the neutralization of the UAV in a potentially dangerous direction. In addition, on the base of results of the model, this approach can be used for the protection of other electronic warfare and air defense systems with higher likelihood of destruction and neutralization of the drones.

Retrieval and uncertainty analysis of stochastic parameter in atmospheric boundary layer model

The eddy viscosity is an important parameter in the atmospheric boundary layer meteorology, and we usually cannot determine their exact values by direct measurements, but we can only obtain an approximate range by indirect approximate method. In this paper, the eddy viscosity in the stochastic general Ekman momentum approximation model is used for the retrieval research and uncertainty analysis. The main purpose of retrieval is to reduce the uncertainty and narrow the approximate range of eddy viscosity. First, the polynomial chaos-ensemble Kalman filter and the wind observations are used for eddy viscosity retrieval and uncertainty reduction. The main idea of this method is to replace the Monte-Carlo method with polynomial chaos in the uncertainty quantification of ensemble Kalman filter, and thusavoiding the consumption of computing resources brought by massive samples. The goal of uncertainty quantification is to investigate the effect of uncertainty in the eddy viscosity on the model and to subsequently provide a reliable distribution of simulation results. Then two numerical experiments are implemented, i.e. experiment I in which the eddy viscosity is assumed to be constant, and experiment Ⅱ in which the eddy viscosity is assumed to be a vertically varying random parameter. The uncertainty of eddy viscosity in experiment I is reduced quickly, at the same time the mean of eddy viscosity can converge to a reference value. The effect in experiment Ⅱ is also remarkable after 16 data assimilation steps. These results show that the polynomial chaos-ensemble Kalman filter is an effective and fast method of solving the posterior distribution of eddy viscosity and reducing the uncertainty of eddy viscosity. Finally, we calculate the prior distribution of wind speed according to the prior distribution of eddy viscosity and identify the heavy uncertainty area in wind speed. The results indicate that the posterior distribution of eddy viscosity solved with wind observations in the big uncertainty area is more accurate, which provides an important guidance for selecting the location of observation points.

Ionospheric response to winter stratosphere/lower mesosphere jet stream in the Northern Hemisphere as derived from vertical radio sounding data

We study the effects of the middle atmosphere dynamics on the mid-latitude and subauroral ionosphere during the winter jet stream that occurred at the stratosphere/lower mesosphere heights in the Northern Hemisphere over 2008–2013. The used ionospheric data were obtained from measurements taken at the vertical sounding ionosonde chain covering the entire Eurasian continent. We reveal regional features of the F2-layer ionospheric response to dynamic processes during the winter circumpolar vortex evolution in the strato-mesosphere. The variations in the ionospheric parameters observed at different longitudes in the Northern Hemisphere significantly depended on the ionosonde position relative to the jet stream zone in the strato-mesosphere. The difference in critical frequency values for the ionosondes spaced longitudinally by only 15–20° could reach about 1.5–2 MHz, depending on the observation point location under the jet stream or off the latter. We consider the molecular gas upwelling/downwelling to/from the lower thermosphere in active regions of circulation as a mechanism for the underlying atmosphere impact on the ionosphere. Irregular variations in the ionospheric parameters could also be caused by wave disturbances of various spatial and temporal scales (including internal gravity waves) propagating into the thermosphere from the underlying atmosphere. The mesoscale wave generation source at the strato-mesospheric heights was associated with baroclinic instabilities in the spatially non-uniform, high-velocity winter jet stream.

Information Entropy in Predicting Location of Observation Points for Long Tunnel

Based on the Markov model and the basic theory of information entropy, this paper puts forward a new method for optimizing the location of observation points in order to obtain more information from limited geological investigation. According to the existing data from observation points data, classification of tunnel geological lithology was performed, and various lithology distribution were determined along the tunnel using the Markov model and theory. On the basis of the information entropy theory, the distribution of information entropy was obtained along the axis of the tunnel. Therefore, different information entropy could be acquired by calculating different classification of rocks. Furthermore, uncertainty increases when information entropy increased. The maximum entropy indicates maximum uncertainty and thus, this value determines the position of the new drilling hole. A new geology situation will be decided by the maximum entropy for the lowest accuracy. Optimal distribution will be obtained after recalculating, using the new location of the geology situation. Taking the engineering for the Bashiyi Daban water diversion tunneling in Xinjiang as a case, the maximum information entropy of the geological conditions was analyzed by the method proposed in the present study, with 25 newly added geology observation points along the axis of the 30-km tunnel. The results proved the validity of the present method. The method and results in this paper may be used not only to predict the geological conditions of underground engineering based on the investigated geological information, but also to optimize the distribution of the geology observation points.

Nondestructive damage detection in deteriorated girders using changes in nodal displacement

The use of static and dynamic responses as inputs in the evaluation procedures of concrete structures has been discussed for many years. With the aim of contributing to efficient structural health monitoring approaches, the present study attempts to develop an estimation method that utilizes only displacement data for detecting structural damage. The approach is based on the correlation between structural damage and variations in measured responses. Specifically, two new damage indicators—displacement assurance criterion (DAC) and displacement-based index (DBI)—are introduced and employed in numerous scenarios to determine damage properties. Parametric studies are performed by a finite-element analysis to verify the correlation of DAC with increasing deterioration and the sensitivity of DBI for identifying the location of damage. In addition, the influence of parameters that affect the accuracy of the proposed methods, such as number of measurements and location of observation points, is also examined. The results demonstrate that DAC can properly indicate the occurrence of degradation in structures and DBI can be utilized as a suitable pointer for damage localization.

Dusty plasma at the surface of the moon

A theoretical model that provides a self-consistent description of the concentrations of photoelectrons and dust particles located over the illuminated part of the lunar surface is presented. The model takes account of the observation point location and the effects of production of photoelectrons at the surfaces of the Moon and dust particles, the dynamics of dust particles in the electric and gravitational fields, and the charging of dust particles through their interaction with the solar radiation photons, the solar wind electrons and ions, photoelectrons, etc. An expression that describes the distribution of photoelectrons over the illuminated part of the lunar surface is obtained. The size and elevation distributions of the charged dust particles located over the illuminated part of the lunar surface are calculated for different angles between the local normal and the direction to the Sun. It is shown that no substantial restrictions are imposed on the choice of the landing site for future lunar spacecraft missions aimed at studying the near-surface dust on the Moon.