Specific Terrain Research Articles

Icing detection method of 500 kV overhead ground wire with tangent tower under special terrain based on vertical tension measurement technology

The operation reliability of the power grid and the stability of social production are seriously threatened by the icing of the overhead line. The equivalent ice thickness (EIT) is to convert different densities and shapes of ice into the uniform annular ice with density of 0.9 g/cm3. Although many methods for calculating EIT of transmission line conductors have been proposed, there are lack an effective monitoring method of EIT for 500 kV ground wire with tangent tower under the special terrain where “the virtual lowest point” of the ground wire appears in the condition of large height difference. Therefore, a calculation method of EIT for 500 kV ground wire with tangent tower under the special terrain based on vertical tension measurement technology is proposed. That is the iterative method is used to preset different EITs. Then the calculated vertical tension under the preset values are solved by the established ground wire state equation and vertical tension equation. The EIT can be obtained when the calculated vertical tension is equal to the measured vertical tension. The comparison between the artificial observed EIT and the calculated EIT is carried out for two practical cases of 500 kV ground wire in the mountainous area of southern China. The results show that the absolute error is less than 2 mm, which verify the two values are in strong agreement. The corresponding finite element simulation models are established. A comparative study between the simulated EIT and the calculated EIT is carried out. The results show that the relative error is less than ±10% under severe icing from 10 mm to 30 mm and the absolute error is less than 1 mm under mild icing of 5 mm, which verify the two values are highly consistent. Finally, the application effect of this method in practical cases is analyzed.

Tapered whisker reservoir computing for real-time terrain identification-based navigation

This paper proposes a new method for real-time terrain recognition-based navigation for mobile robots. Mobile robots performing tasks in unstructured environments need to adapt their trajectories in real-time to achieve safe and efficient navigation in complex terrains. However, current methods largely depend on visual and IMU (inertial measurement units) that demand high computational resources for real-time applications. In this paper, a real-time terrain identification-based navigation method is proposed using an on-board tapered whisker-based reservoir computing system. The nonlinear dynamic response of the tapered whisker was investigated in various analytical and Finite Element Analysis frameworks to demonstrate its reservoir computing capabilities. Numerical simulations and experiments were cross-checked with each other to verify that whisker sensors can separate different frequency signals directly in the time domain and demonstrate the computational superiority of the proposed system, and that different whisker axis locations and motion velocities provide variable dynamical response information. Terrain surface-following experiments demonstrated that our system could accurately identify changes in the terrain in real-time and adjust its trajectory to stay on specific terrain.

Adaptive Robust Autonomous Obstacle Traversal Controller for Novel Six-Track Robot

The separate control method of flippers and the movement of the mass center makes the active articulated tracked robot unable to realize higher-level motion and difficult to adapt to rough and complex obstacle terrain. In this paper, a new design method of distributed autonomous obstacle traversal controller for the novel six-track robot is proposed. The controller establishes a unified control framework that includes all degrees of freedom of the robot so that the center of mass tracking error and flipper motion tracking error can converge simultaneously to achieve obstacle traversal independently of specific terrain or tasks. First, the forward kinematics model and differential kinematics model of tracked robot are established to generate 3D motion, including flipper angular velocity and body traction velocity. Then, the differential drive robot model is extended into the differential kinematic model to eliminate the slip effect during obstacle traversal. Finally, the feedback control law of the control system and the optimal solution for the singular position of the robot structure are established. In addition, several simulation experiments and physical prototype experiments in different obstacle terrains are executed. In the virtual simulation experiment, the average trajectory error of the flipper is about 0.029 m. In the physical prototype experiment, compared to the manual remote controller and the prior art controller, the average error norm of the center of mass is reduced by 40.7% and 13.5%, respectively; the maximum slip norm is reduced by 34.6% and 19.9%, respectively; and the obstacle crossing time is reduced by 21.3% and 9.3%, respectively, and they validate the accuracy and effectiveness of the designed controller.

Study to evaluate the effect of terrain surface on performance of a wind farm in Ninh Thuan province, Vietnam

Topography is one of the important factors directly related to the distribution of wind resources, so it plays an important role in determining the layout and operation efficiency of wind power farms. In this research, we use a combination of Computational Fluid Dynamics (CFD) method and Geographic Information Systems (GIS) data to determine suitable locations for building wind turbines in complex terrain conditions. The selected region to build the analytical model is an area with many hills and mountains adjacent to the East Sea, in Thuan Nam and Ninh Phuoc districts, Ninh Thuan province. The first part, this article will provides a general method for determining the best locations for installation of wind turbines according to specific terrain conditions. Then, apply this method to build accurate 3D models for the area, the models are meshed by hexagonal elements combined with tetrahedron elements with side lengths of 200m. The results obtained from the models are the distributions of wind speed by altitude at specific locations such as mountain peaks, mountain slopes, valleys of the area pointed out. Based on these results, the locations with high and stable wind speed, suitable for wind turbine operation are suggested. In addition, the article also presents some locations where wind with high turbulence or eddy winds may appear, which may adversely affect turbine performance. Finally, the paper gives an optimal location map for a wind farm with a capacity of less than 100MW using a turbine with a 4MW capacity.

CNN-based battlefield classification and camouflage texture generation for real environment

It is critical to understand the environment in which the military forces are deployed. For self-defence and greater concealment, they should camouflage themselves. Camouflage is being used by the defence system to hide its personnel and equipment. The industry demands an intelligent system that can categorise the battlefield before generating texture for camouflaging their assets and objects, allowing them to adopt the conspicuous features of the scene. In this study, a CNN-based battlefield classification model has been developed to learn background information and classify the terrain. The study also intended to develop the texture for specific terrain by matching its salient features and boosting the effectiveness of the camouflage. Saliency maps have been used to measure the effectiveness of blending a camouflaged object into an environment.

Study on Critical Factors Affecting Tidal Current Energy Exploitation in the Guishan Channel Area of Zhoushan

As a new type of clean and renewable energy, tidal current energy has attracted more and more attention from scholars. The Zhoushan Guishan Channel area (GCA) is an important part of the East China Sea port area, with strong currents due to its special terrain. In order to more comprehensively evaluate the characteristics of tidal energy development near the GCA, this paper uses the MIKE21 FM hydrodynamic model to simulate the tidal hydrodynamic process in the Zhoushan sea area and verifies the reliability of the model through the measured data. Based on the results of numerical simulations, the energy flow density, frequency of flow rate occurrence, flow asymmetry, flow rotation, and effective flow time that can be exploited are considered as the key factors affecting the development of tidal current energy. The distribution characteristics of each influencing factor in the region and the different influences on tidal current energy development are analyzed. Numerical simulations show that the average high-tide velocity in the GCA is lower than the ebb-tide velocity, and the duration of the high tide is also shorter than that of the ebb tide, which has a higher flow velocity than the surrounding area. The annual average energy flow density in the GCA is the highest at 4520 W/m2, and the spatial distribution is uneven. The resource level in the central part is much higher than that at both ends of the waterway. Three sections, i.e., A-A′, B-B′, and C-C′, with different key influence factors are selected for specific analysis, and it is concluded that the tidal energy development conditions are relatively superior near the B-B’ section in the middle of the GCA, and the exploitable power calculated using the Flux method is about 24.19 MW. The discussion of the results provides a certain reference for the development of local tidal current energy. These key factors affecting tidal current energy development can also be applied to assess the suitability of tidal current energy resource development in other regions.

A Walking Claw for Tethered Object Retrieval

Abstract Mobility and manipulation are often considered separately, with independent degrees-of-freedom (DOF) for each. However, here we show that using the legs for both walking and grasping increases the versatility of both tasks. Our robot has four DOF: drive and lift for left and right pairs of legs. The legs use a reduced actuation Klann mechanism. The lift DOF rotates the entire trajectory of the legs, which enables gait modulation, climbing, and grasping. This demonstrates the feasibility of a novel operational concept: a robot that can approach, climb onto, and securely grasp an object that can then be lifted via a load-bearing tether. Specifically, we show the kinematics to enable small robots to climb onto rectangular objects up to 67% robot height and grasp objects between 43% and 72% of the robot’s length. With these kinematics, a robot can be scaled for specific terrains and object sizes, with potential application in construction, search and rescue, and object retrieval.

A novel statistical method for long-term coronavirus modelling

Background: Novel coronavirus disease has been recently a concern for worldwide public health. To determine epidemic rate probability at any time in any region of interest, one needs efficient bio-system reliability approach, particularly suitable for multi-regional environmental and health systems, observed over a sufficient period of time, resulting in a reliable long-term forecast of novel coronavirus infection rate. Traditional statistical methods dealing with temporal observations of multi-regional processes do not have the multi-dimensionality advantage, that suggested methodology offers, namely dealing efficiently with multiple regions at the same time and accounting for cross-correlations between different regional observations. Methods: Modern multi-dimensional novel statistical method was directly applied to raw clinical data, able to deal with territorial mapping. Novel reliability method based on statistical extreme value theory has been suggested to deal with challenging epidemic forecast. Authors used MATLAB optimization software. Results: This paper described a novel bio-system reliability approach, particularly suitable for multi-country environmental and health systems, observed over a sufficient period of time, resulting in a reliable long-term forecast of extreme novel coronavirus death rate probability. Namely, accurate maximum recorded patient numbers are predicted for the years to come for the analyzed provinces. Conclusions: The suggested method performed well by supplying not only an estimate but 95% confidence interval as well. Note that suggested methodology is not limited to any specific epidemics or any specific terrain, namely its truly general. The only assumption and limitation is bio-system stationarity, alternatively trend analysis should be performed first. The suggested methodology can be used in various public health applications, based on their clinical survey data.

Effectiveness and heterogeneity evaluation of regional collaborative governance on haze pollution control: Evidence from 284 prefecture-level cities in China

• Regional collaborative governance significantly reduces haze pollution. • The 31 provinces in China are divided into 10 collaborative governance regions. • Collaborative governance on haze pollution reduction has temporal and spatial heterogeneity. • The “free-rider” effect has obvious temporal and regional heterogeneity. The impact of collaborative governance on the reduction of haze pollution has always been a hotly debated topic in environmental protection research. First, the present study aims to examine the effectiveness of collaborative governance on haze pollution control by using panel data of 284 Chinese cities during 2008–2018. Second, social network analysis is used to divide 31 provinces into 10 collaborative governance regions. Third, the temporal and spatial heterogeneity of collaborative governance on the reduction of haze pollution in each region is investigated through the GTWR model, and the underlying mechanism of the heterogeneity of collaborative governance is explained in detail through the “free-rider” effect. The results show that collaborative governance has a positive effect on haze pollution reduction, in which government effort is indispensable. The concentration of PM2.5 decreased by 5.658 μg/m 3 with every 1% increase in the collaborative governance level. The collaborative governance effect shows an obvious time trend and regional difference, and the effect of haze control in each collaborative governance region basically shows a fluctuating trend due to the updating of environmental regulations. The developed regions have better control effect in haze pollution control, and the eastern coastal regions are better than other regions. The temporal and spatial distribution characteristics of the “free-rider” effect are similar to those of collaborative governance; the "free-rider" effect is more apparent in less-developed areas and areas with special terrain. Central government supervision is essential for enhancing regional collaborative governance and avoiding the “free-rider” effect. At the same time, it is necessary to improve regional collaborative governance through the clear division of responsibilities and regulatory rules.

Modeling LoRa Communications in Estuaries for IoT Environmental Monitoring Systems

Low-power wide-area networks (LPWANs) are extending beyond the conventional terrestrial domain. Coastal zones, rivers, and wetlands, among others, are nowadays common deployment settings for Internet-of-Things nodes where communication technologies such as Long Range (LoRa) are becoming popular. In this article, we investigate large-scale fading dynamics of LoRa line-of-sight (LoS) links deployed over an estuary with characteristic intertidal zones, considering both shore-to-shore (S2S) and shore-to-vessel (S2V) communications. We propose a novel methodology for path-loss prediction which captures: 1) spatial; 2) temporal; and 3) physical features of the RF signal interaction with the environmental dynamics, integrating those features into the two-ray propagation model. To this purpose, we resort to precise hydrodynamic modeling of the estuary, including the specific terrain profile (bathymetry) at the reflection point. These aspects are key to accounting for a reflecting surface of varying altitude and permittivity as a function of the tide. Experimental measurements using LoRa devices operating in the 868-MHz band show major trends in the received signal power in agreement with the methodology’s predictions.

An All-Sky Scattering Index Derived from Microwave Sounding Data at Dual Oxygen Absorption Bands

Combining the temperature sounding channels near 118 GHz onboard Fengyun-3D (FY-3D) with channels near 50 GHz makes it possible to obtain the spatial and vertical distributions of the clouds through a cloud emission and scattering index (CESI). Previous research has shown its advantages in cloud detection over oceans. In this study, the CESI method is expanded and validated under different surface conditions, and angular corrections are conducted to remove the effect of viewing angles. The landfall process of Typhoon MANGKHUT and a case over special terrain are chosen to investigate its sensitivities to different surface types. It is found that the cloud spatial distribution is well demonstrated in both of the cases. Moreover, the CESI vertical distributions are compared with the Global Precipitation Measurement (GPM) hydrometeor profiles. The results show that CESIs are highly related to the GPM hydrometeor profiles in all of the conditions, and the correlations with the sea surface vary with the weighting functions of the matched channels, while the phenomenon is not obvious for the land surface. In addition, the validation results show that the new threshold combination for different surface types at different heights can be more effective for cloud identification. The probability density distribution for most of the channels of the screened-out clear sky data approximates a Gaussian distribution well, and these radiances can be well assimilated into the numerical weather prediction models.

An evaluation of the use of IMERG products for representing drought in a typical rocky karst region experiencing rocky desertification in Guangxi, China

ABSTRACT Droughts are very common and threatening disasters in regions where groundwater storage is difficult. High-resolution satellite estimations such as the Integrated Multi-satellitE Retrievals for Global Precipitation Measurement (IMERG) provide a new solution for drought monitoring in areas with this special terrain. In this study, the pre-evaluation of products is conducted before drought monitoring, then based on the Standardized Precipitation Index (SPI), the application in drought presentation is evaluated over Guangxi, a Chinese province where the karst areas are being eroded by rocky desertification. The main results are as follows: (1) The monthly estimating by IMERG products is reliable, and the best performance for daily scale appears in regions with rich rainfall and severe rocky desertification, while high errors occur in the same place. (2) IMERG products can be an alternative to gauge-based data in drought monitoring over karst rocky desertification regions like Guangxi, where multiple droughts happened from 2000 to 2017. The SPI of IMERG_F has the best spatial consistency, and better results are presented over humid rocky desertification regions.

Learning-Based Shared Control Using Gaussian Processes for Obstacle Avoidance in Teleoperated Robots

Physically inspired models of the stochastic nature of the human-robot-environment interaction are generally difficult to derive from first principles, thus alternative data-driven approaches are an attractive option. In this article, Gaussian process regression is used to model a safe stop maneuver for a teleoperated robot. In the proposed approach, a limited number of discrete experimental training data points are acquired to fit (or learn) a Gaussian process model, which is then used to predict the evolution of the process over a desired continuous range (or domain). A confidence measure for those predictions is used as a tuning parameter in a shared control algorithm, and it is demonstrated that it can be used to assist a human operator by providing (low-level) obstacle avoidance when they utilize the robot to carry out safety-critical tasks that involve remote navigation using the robot. The algorithm is personalized in the sense that it can be tuned to match the specific driving style of the person that is teleoperating the robot over a specific terrain. Experimental results demonstrate that with the proposed shared controller enabled, the human operator is able to more easily maneuver the robot in environments with (potentially dangerous) static obstacles, thus keeping the robot safe and preserving the original state of the surroundings. The future evolution of this work will be to apply this shared controller to mobile robots that are being deployed to inspect hazardous nuclear environments, ensuring that they operate with increased safety.

Psychiatrization of adoption practices in contemporary Poland.

In this article, I propose to take a closer look at the practices of kinning in the context of adoption in contemporary Poland. I am interested in the social production of this ‘unfamiliar kind of kinship' and the positions of various actors involved in defining the “adoptable” children and the “families of excess” capable of adopting. My focus will be on the ways in which the psy-knowledge and practices are implied in these social processes of defining and delimiting the norm, the proper, and the ideal. This process can be called a progressing psychiatrization of kinning, this time developing on a specific terrain of adoption (i.e., the most desired state of exception from ideal family—nuclear, heteronormative, based around married, and non-divorced couple). I will consider both top-down and bottom-up processes within which the individuals, state institutions, and psy-knowledge interact. Thus, I propose to look at a sub-process of psychiatrization, which takes place in the specific ethnographic context at the intersection of family and social policies, medicalization and psychologization of familial relations, and troubled, disconnected biographies. Throughout the article, I discuss how the adoptive families become patient-consumers within the system of healthcare. It is despite the fact that when they enter the adoption network, they start to take part in the political process of solving the social problem. In fact, they become a part of the network, which enables privatization of the social problem and works toward individualizing the responsibility for solving it.

Analysis of Intelligent Monitoring and Early Warning in High Side Slope Areas

As a large amount of excavation, filling and compaction are required during the construction of railroad projects, and slope cutting is also required in special terrain areas, which destroys the original geological environment balance of the soil, and under the influence of environmental and engineering factors, geological disasters such as landslides and collapses are easily induced. In this paper, a scientific method of slope stability discrimination is firstly proposed on the basis of monitoring and early warning. By combining two methods of engineering displacement monitoring and numerical simulation analysis for monitoring and early warning, it circumvents the problem of using a single method with poor accuracy and improves the efficiency of the early warning system. Compared with the traditional monitoring and early warning, this paper proposes the method of linkage early warning, which summarizes the factors that have a great influence on the stability of slope and obtains the corresponding prediction information in advance, and applies the data to the numerical simulation to obtain the stability change of slope, so that the early warning can be released in advance and the countermeasures can be taken to reduce the loss.

Significant influence of aerosol on cloud-to-ground lightning in the Sichuan Basin

The effects of aerosols under special terrain on lightning activities in the Sichuan Basin (SB) are studied using the cloud-to-ground (CG) lightning data and aerosol optical depth (AOD) data from 2010 to 2018. Interesting results show that the topographic drop plays an important role in the process of aerosol affecting lightning. The great topographic drop in the western SB is conducive to the production of CG lightning. Both the CG lightning production and AOD in the northwest and southwest of the basin decrease in fluctuation during the study period. It can be inferred that the reduction of aerosol results in the decrease of lightning activity. Due to the topographic drop in the northwest of the basin being greater than that in the southwest, the correlation of 0.64 between AOD and CG lightning in the northwest of the basin is larger than that of 0.31 in the southwest. Since the lightning activity in SB generally occurs at night, the aerosol-radiation interaction (ARI) has an insignificant influence on the occurrence of convection. Under this condition, it can be inferred that the aerosol-cloud interactions (ACI) are dominant over SB region. These could better support the reduction of lightning generation.

Development of unified classifier of special terrain maps using geoinformation technologies

A method for creating a unified classifier of special terrain maps using geoinformation technologies is presented. The existing classifiers of maps of the operational and tactical situation, special and topographic terrain maps used in the Armed Forces of the Republic of Belarus are analysed. Using the software products of the design bureau «Panorama», a methodology of developing new classifiers for geoinformation and traditional approaches is described. The urgency of creating the first unified digital classifier of special terrain maps for the geoinformation approach, which contains all available special terrain maps and allow you to use them in conjunction with maps of the operational-tactical situation and electronic topographic terrain maps crosslinking, is substantiated. The relevance of the creation of digital classifiers of special terrain maps by scale for the traditional approach involving the development of maps for analog printing is substantiated. In the created digital classifiers, for the first time, a system of classification and coding of terrain objects was used for them, which is based on the hierarchical method of classification of information of the first subset and the faceted method of classification of information of the second subset. The developed classifiers have a unified colour palette and cartographic fonts. Examples of the created symbols of the classifiers of special terrain maps are given. It is concluded that it is necessary to use the developed unified classifier of special terrain maps in the Armed Forces of the Republic of Belarus.

Методика подготовки экспериментальных данных для информационно-интеллектуальной системы проектирования сетей лесовозных дорог

The article describes a technique for obtaining experimental data for the purpose of optimal distribution of the forest transport network on a specific terrain model. Particular attention was paid to the issue of the operability of primary forest transport routes, in particular, the requirements for the strength of trunk lines, which is of fundamental importance when establishing the optimal distance between long-term roads. The operability of the trunk lines was experimentally investigated, while the scheme of the movement of tractors along the ring was used. Based on experimental data, certain values of track depth, relative humidity, density and the number of impacts depending on the number of passes were obtained. In the course of the experimental study, functional dependences of the increase in the depth of the track on the number of passages were established and calculated, taking into account the physical and mechanical properties of forest soils. During the tests, some fundamental differences were recorded in the process of track formation during the movement of wheeled and tracked tractors. It is important for the development of measures to reduce the seasonality of forest transport, especially during the autumn-spring thaw. Comparative tests of tracked and wheeled tractors when they move along a reinforced track have shown that a reinforced track when moving a wheeled tractor is able to withstand a significantly greater number of passes than when moving a tracked tractor. For the statistical evaluation of the experiments carried out, it was determined what errors could be caused by replacing the parameter with its point estimate. Analysis of statistical processing of the observation results showed that all the series, as a rule, correspond to the law of normal definition, which is determined by the ratio of the symmetry and kurtosis indicators to their average errors. These relations are determined within the limits of permissible deviations, therefore, asymmetry and kurtosis in this case do not matter significantly.

The mineralization and sequestration of soil organic carbon in relation to gully erosion

Water erosion exerts a profound, but uncertain effect on the terrestrial carbon cycle. Therefore, the soil erosion intensity is uncertain in different terrains. Previous studies have focused on the slope and intensity of soil erosion, while ignored the special terrain such as gully created by erosion. To advance the understanding of the mineralization dynamics of soil organic carbon (SOC) from the micro perspective, the relationship between soil erosion and carbon source and sink is expected to be further improved. In this study, we explored the impact of water erosion on SOC mineralization in the areas of gully erosion in Qingyuan mountain, Jiangxi, China by combining the 137Cs technique and laboratory incubation experiment, calculated the first-order kinetic model parameters of the SOC mineralization of bulk soil and aggregates in the area of gully erosion, and estimated the correlation between the factors that may affect SOC mineralization. The results showed that (1) the mineralization rates of SOC in the bulk soil and aggregates showed fluctuations and reached a peak, and finally became stable. The soil erosion intensity was significantly positively correlated (p < 0.05) with the cumulative mineralization of SOC. (2) The cumulative mineralization in the depositional area (489.67 mg kg−1) was higher than that in the erosional area (402.69 mg kg−1). (3) Soil macroaggregates were the main contributors to SOC mineralization (63.56%–92.28%), and the soil macroaggregate organic carbon mineralization dynamics was more sensitive to soil erosion. Additionally, significant effects (p < 0.05) of soil mechanical composition, capillary pores, saturated water content, and contents of carbon and nitrogen on SOC mineralization were observed. Erosion increased the risk of SOC loss by mineralization of SOC, especially in macroaggregates. The deposition process caused the enrichment and burial of SOC, and the background level of SOC and the content of macroaggregates in the depositional area were higher than those in the erosional area. The results showed that soil erosion increased the risk of SOC loss by mineralization of SOC based on laboratory simulation. The present study aiming at examining the effect of gully erosion on the mineralization and sequestration of SOC provides important insights into balancing the global carbon budget.

Study on water hammer protection of the siphon breaking structure in the water supply system

Abstract An appropriate water hammer protective scheme is a significant concern in the operation of water supply projects. According to the special terrain in the water supply project, which forms a siphon breaking structure at the end of the pipeline, three protective schemes were proposed and compared: single vacuum breaking valve (VBV) scheme, VBV and air valve scheme, and VBV and one-way surge tower scheme. Based on the control standards of pipe pressure, the three protective schemes were assessed in terms of suppressing the negative pressure caused by a pump trip accident. The results show that the siphon breaking structure with the VBV can achieve good effect protection only in a limited range of pipelines. In the VBV and air valve scheme, the pressure oscillations were obviously caused by repeated inlet and exhaust of the air valves. To avoid supplementing too much gas in the pipe by air valves, which will result in a gas column bridging phenomenon, the VBV and one-way surge tower scheme is proposed and can better meet the requirement of the pressure control standard.