Types Of Ground Surfaces Research Articles

UAV Imagery-based Automatic Classification of Ground Surface Types for Earthworks

UAV Imagery-based Automatic Classification of Ground Surface Types for Earthworks

Isometric mapping algorithm based GNSS-R sea ice detection

<abstract> <p>Global navigation satellite system reflectometry (GNSS-R) is based on satellite signals' multipath interference effect and has developed as one of the important remote sensing technologies in sea ice detection. An isometric mapping (ISOMAP)-based method is proposed in this paper as a development in sea ice detection approaches. The integral delay waveforms (IDWs), selected from February to April in 2018, derived from TechDemoSat-1 (TDS-1) Delay-Doppler maps (DDMs) are applied to open water and sea ice classification. In the first, the model for extracting low-dimensional coordinates of IDWs employs the randomly selected 187666 IDW samples, which are 30% of the whole IDW dataset. Then, low-dimensional coordinates of IDWs are used to train three different classifiers of support vector machine (SVM) and gradient boosting decision tree (GBDT), linear discriminant algorithm (LDA) and K-nearest neighbors (KNN) for determining the sea ice and sea water. The remaining 437889 samples, about 70% of the whole datasets, are used to validate with the ground surface type from the National Snow and Ice Data Center (NSIDC) data provided by the National Oceanic and Atmospheric Administration (NOAA). The algorithm performance is evaluated, and the overall accuracy of SVM, GBDT, LDA and KNN are 99.44%, 85.58%, 91.88% and 98.82%, respectively. The sea ice detection methods are developed, and the accuracy of detection is improved in this paper.</p> </abstract>

Methods of the terrain allowable slope determining for safe operation of specialized equipment under the non-stationary load action

The operation of modern high-tech equipment requires a clear delineation of safe conditions for its operation. To a large extent, this applies to machines that move and work on untreated soil surface: forestry machinery, agricultural machinery, road construction machinery, military equipment, and so on. Asymmetry of the location of the working bodies, work on surfaces with a lateral slope, non-stationary interaction with the working environment - these are the factors that increase operational risks. Objective of this study is to establish the limits of safe operation of specialized machines operating on a rough surface with a slope to the horizon. The methods of determining safe slopes for the above-described equipment in the conditions of its non-stationary interaction with the subject of work are considered in the work. In particular, dangerous slopes that can cause the car to overturn or roll sideways are identified. The realization of this goal is achieved by building a mathematical model and appropriate calculation schemes that cover both possibilities of loss of stability. Graphs are plotted to display the maximum slopes due to the overturning and sliding of the machine on the slope for the specified operating loads. The integral characteristic of the slope limit value covers both of the above risks. The application of the proposed methods is illustrated by the calculation of the safe slope for firing tanks for different angles of deviation of the gun from the surface of the movement on the slope and the type of ground surface of the movement. The following results were obtained: methods for calculating the allowable slopes for the possibility of operating specialized machines on them, taking into account soil conditions, and demonstrated the application of the approach to the case of military equipment. The use of these results is a necessary factor for the implementation in the design of technological processes for specialized machines in order to minimize operational risks.

Managing the invasive plant Carpobrotus edulis: is mechanical control or specialized natural enemy more effective?

Carpobrotus edulis is an invasive clonal plant with drastic effects on biodiversity and functioning of coastal ecosystems. In recent years, authorities and land managers have implemented diverse management strategies that usually focus on mechanical removal and chemical control. However, applying mechanical control to remove C. edulis may cause indirect adverse effects since it could increase the probability of spreading new propagules, which do not lose their physiological activity. Therefore, reducing the physiological activity of these plant fragments should be a priority to avoid their spread and re-rooting. Our goal was to assess the plant regeneration capacity after applying mechanical control (i) when placing the plant material on different types of ground surface (on sand, on stones and using rooted plants as control) and (ii) combined with the attack of specialized herbivores (the soft scale Pulvinariella mesembryanthemi). To achieve this, we evaluated how these two factors (ground surface and herbivory) affected the plant physiological activity, its survival and re-rooting, biometric measurements, shoot and root nutrient composition and biochemical parameters (total phenols and tannins). Regardless of the ground surface type, our results indicated that the specialist herbivore greatly affected the C. edulis parameters studied. The attack of P. mesembryanthemi stimulated the plant defence mechanisms, even in those individuals with less photosynthetic activity. Furthermore, P. mesembryanthemi severely reduced the biomass and volume of plant material. Decomposition of C. edulis was accelerated by the combination between the inoculation of P. mesembryanthemi and placing the plants on the stones ground surface. Overall, preventing plant re-rooting by avoiding connection to the soil is an effective method of reducing its viability after the eighth-tenth month. After applying mechanical control, we recommend placing C. edulis fragments over an inert ground surface to avoid re-rooting, which would favour its death. We conclude that the combination of mechanical control and P. mesembryanthemi or even direct inoculation with this specialist herbivore could help authorities and land managers to improve management strategies for C. edulis.

The Effects of Landscape Elements on the Breeding Sites of Bloodsucking Midge

Forcipomyia taiwana, a bloodsucking midge that is one of the most irritating biting pests in Taiwan, has raised widespread public concern. However, we have little information about the extent to which landscape factors affect their potential habitats. As a result, landscape professionals do not have enough information to implement preventive strategies to control midges. The purpose of this study is to investigate the relationship between landscaping and algae growth for larval breeding sites of Forcipomyia taiwana. The intent is to determine the environmental strategies that make the planned landscape unsuitable for midges to breed. GIS based on data collected from 16 constructed landscape sites (317,187 m2 in total) was utilized to spatially examine the relationship between the occurrence of the algae for midge breeding sites and the ground surface types and planting characteristics in each landscape. The results revealed that the potential midge habitats can be controlled through careful selection of the ground surface, the improvement of the site drainage, and choosing plants with the appropriate characteristics. Apart from choosing the appropriate type of paving surface, the integrity of the paving installation and the coverage of the ecological surface also influence prevention efficacy.

Ultra-Wideband Radio Channel Characteristics for Near-Ground Swarm Robots Communication

Ultra-Wideband (UWB) technology has great potential for the cooperation and navigation among near ground mobile robots in GPS-denied environments. In this paper, an efficient two-segment UWB radio channel model is proposed with considering the multi-path condition in very near-ground environments and different surface roughness. We conducted field measurements to collect channel information, with both transmitter and receiver antennas placed at different heights above the ground: 0cm-20cm. Signal frequency was chosen at 4.3GHz with bandwidth of 1GHz. Three ground coverings were tested in common scenarios: brick, grass and robber fields. The proposed model has enhanced accuracy achieved by careful assessment of dominant propagation mechanisms in each segment, such as diffraction loss due to obstruction of the first Fresnel zone and higher-order waves produced by ground roughness. It is realized that antenna height and distance are the most influential geometric parameters to affect the path loss model. Once the antenna height is known, there exists a breakpoint distance in UWB propagation, which separates two segmentation using the different path-loss mechanism. Different surface types can cause different signal attenuation. Monte Carlo simulations are used to investigate the effects of antenna height, distance, ground surface type on mobile robots swarm communication to find out the antenna height is also a dominant factor on connectivity and the average number of neighbors. Within a certain range, the higher the antenna height and the closer the communication distance, the better the communication performance will usually be. Cramér-Rao lower bound(CRLB) of path loss estimator based on the proposed model is derived to show the relationship between CRLB with height and distance.

Monkey Bar Dimensions Associated with Pediatric Upper Extremity Fractures Show Deviations from United States Product Safety Commission Recommendations.

BackgroundMonkey bar injuries account for the majority of playground injuries, and 34% result in a fracture. Studies have shown that there has been no decline in the number of monkey bar injuries over several decades. Our goal was to focus on fractures of the upper extremity resulting from monkey bar injuries. Additionally, we set out to analyze the dimensions of the monkey bar apparatus on which the injury occurred and determine if they were compliant with those recommended by the United States (US) Product Safety Commission.MethodsA retrospective chart review of all upper extremity injuries seen in a large pediatric orthopedic practice in 2017 was conducted to find all monkey bar-related injuries. Data was collected including age at the time of injury, gender, and injury type. Families of the injured child were contacted to identify the exact location of the injury. On-site measurements were made of the monkey bar apparatus including height, the distance between grips, the circumference of the grip, and ground surface type.ResultsOf 1968 patients seen in 2017, there were 990 upper extremity injuries and 66 monkey bar injuries (98.5% fractures). The average age of those injured on monkey bars was 6.6 ± 1.9 years, 60.6% were males. The average height of the apparatus was 207.32 ± 16.59 cm (range: 176.53-254 cm), the average distance between grips was 35.30 ± 5.62 cm, and the average circumference of the grip was 9.83 ± 1.03 cm. All exceeded the recommended height for preschool children aged 4-5 years (152.4 cm), and 11 of the 30 (36.7%) exceeded this recommended height for school-age children (213.26 cm). For the distance between grips, 23 of the 30 (76.7%) exceeded the preschool recommendation (30.48 cm), and three of 30 (13.3%) monkey bars exceeded the recommendation for school age children (38.1 cm).ConclusionMonkey bar injuries continue to be a common source of upper extremity fractures among young children. There is a high rate of non-compliance with current recommended safety standards.

Zonal classification of microclimates and their relationship with landscape design parameters in an urban park

Microclimates in urban areas arise through the interaction between prevailing weather conditions and landscape design parameters. A well-arranged landscape creates a pleasant outdoor environment. Additionally, the classification of microclimates helps to illustrate variations therein and analyze influencing factors. This study classified microclimate zones (MZs) based on a statistical method and identified influential landscape design parameters with the aim of enhancing human comfort. We conducted our study at Yeouido Park in Seoul, Korea, which has various landscape design parameters, including tree canopy cover and ground surface type. A novel MZ classification method was developed in this study, then stepwise regression was used to analyze the relationship between microclimate and landscape design parameters. It was found that the MZ classification effectively demonstrated spatial microclimatic differences and characteristics on a park scale. The efficiency with which trees improved the microclimate depended on the ground surface type. However, the significant effects of landscape design parameters on the microclimate and human comfort differed by season and time of day. This study provides a statistical method for analyzing an urban microclimate and serves as a reference regarding how to effectively modify the meteorological environment on a microscale via landscape design, in both summer and winter urban outdoor spaces.

Evaluating passing ability in association football

Abstract In this paper, the passing ability of football players is determined by building three generalized additive mixed models that each explains a different aspect of a pass’ success: difficulty, risk and potential. The models are built on data from the 2014–2016 seasons of the Norwegian top division Eliteserien, and their predictive power is tested on the 2017 season. The results provide insight into the factors affecting the success of a pass in Eliteserien. These include the location of the pass, the relationship to previous passes and to situations such as throw-ins, corners, free kicks or tackles, as well as conditions specific to the Eliteserien, such as the time of season and the ground surface type. Finally, the key pass makers in the league are identified.

Estimating Spatiotemporal Information from Behavioral Sensing Data of Wheelchair Users by Machine Learning Technologies

Recent expansion of intelligent gadgets, such as smartphones and smart watches, familiarizes humans with sensing their activities. We have been developing a road accessibility evaluation system inspired by human sensing technologies. This paper introduces our methodology to estimate road accessibility from the three-axis acceleration data obtained by a smart phone attached on a wheelchair seat, such as environmental factors, e.g., curbs and gaps, which directly influence wheelchair bodies, and human factors, e.g., wheelchair users’ feelings of tiredness and strain. Our goal is to realize a system that provides the road accessibility visualization services to users by online/offline pattern matching using impersonal models, while gradually learning to improve service accuracy using new data provided by users. As the first step, this paper evaluates features acquired by the DCNN (deep convolutional neural network), which learns the state of the road surface from the data in supervised machine learning techniques. The evaluated results show that the features can capture the difference of the road surface condition in more detail than the label attached by us and are effective as the means for quantitatively expressing the road surface condition. This paper developed and evaluated a prototype system that estimated types of ground surfaces focusing on knowledge extraction and visualization.

Passivity Analysis and Control of Humanoid Robots on Movable Ground

Reliable and robust balancing controllers are key elements of whole-body control frameworks for humanoid robots. Passivity-based balancing controllers have been proposed and tested successfully in various scenarios involving different types of ground surfaces. This letter extends the passivity considerations for covering not only the robot and the controller but also the ground floor in order to guarantee an appropriate behavior, even when the underlying ground surface is not stable. The proposed extension is validated with experiments using the humanoid robot TOrque-controlled humanoid RObot (TORO).

Effect of different pavements on human thermal comfort conditions

The urban heat island (UHI) phenomenon and outdoor human thermal comfort may be affected by several factors such as the size of the built environment, the rate of open and green spaces and different types of ground surface covers (e.g., grass and artificial covers) in urban areas. Depending on the types and structures of the pavement/covering materials, which can have effects on the albedo and surface heating, ground surfaces reflect solar radiation or heat the air above them. Pavements that can absorb more solar radiation may turn it into heat, thus warming the air, which in turn heats urban areas and make them uncomfortable for human beings. The present study investigates the effect of different materials on the UHI intensity by considering nine different types of materials (andesite, granite, basalt, travertine, impregnated wood, soil, asphalt, clinker powder and grass) in the Ata botanical garden located in the city center of Erzurum, in the Eastern Anatolia region of Turkey. Temperature data were measured on clear summer days during the month of July and compared in terms of thermal comfort. All measurements were taken 150 cm above the ground at 12:00 p.m. by using an infrared thermometer (CEM-DT-8812). In order to estimate the physiologically equivalent temperature (PET) for each soil type, data were analyzed using the RayMan 2.1 software, and the scores were statistically analyzed with analysis of variance (ANOVA). The differences in mean temperatures were evaluated with Fisher’s least significant difference (LSD) test. The results showed that mean PET scores ranged between 28.9 oC for impregnated wood and 25.9 oC for grass (a difference of 3.0 oC), while the other scores were 26.1, 26.7, 27.1, 27.5, 27.8, 28.5 and 28.5 oC for travertine, granite, andesite, soil, clinker powder, basalt, and asphalt, respectively. The analytical results indicated that all the studied materials create a slight heat stress (23.1-29.0 oC) according to their PET indices and their predetermined comfort intervals. However, the levels of heat stress for impregnated wood, asphalt, and basalt were higher than the others. It was determined that grass, travertine and cube granite are optimal surface materials, since they exhibited a level of heat stress that is close to the comfort range (18.1-23.0 oC).

Experiments in Second Order Sliding Mode Control of a CPG based Spherical Robot

A novel caterpillar inspired rolling gait generation in a spherical robot and its control mechanism is presented in this paper. A rhythmic rolling pattern mimicking Pleurotya caterpillar is produced for the spherical robot locomotion. The pattern is represented by central pattern generators (CPGs)in combination with nonlinear robot dynamics. These rhythmic patterns are controlled by a non-linear high (second) order sliding mode (HOSMC) feedback method, to maintain robot stability and robustness in the presence of matched parameter uncertainties and bounded external disturbances. Design and experimental evaluation of the proposed control strategy for the spherical robot is done on both smooth and rough ground surfaces. Control performance of the robot is measured by virtue of roll angle stability its convergence and wheel velocities. Experimental results validate that proposed second-order HOSMC strategy is more efficient in robust rolling gait control of a spherical robot compared to a first-order SMC on two different types of ground surfaces.

Type of Ground Surface during Plyometric Training Affects the Severity of Exercise-Induced Muscle Damage.

The purpose of this study was to compare the changes in the symptoms of exercise-induced muscle damage from a bout of plyometric exercise (PE; 10 × 10 vertical jumps) performed in aquatic, sand and firm conditions. Twenty-four healthy college-aged men were randomly assigned to one of three groups: Aquatic (AG, n = 8), Sand (SG, n = 8) and Firm (FG, n = 8). The AG performed PE in an aquatic setting with a depth of ~130 cm. The SG performed PE on a dry sand surface at a depth of 20 cm, and the FG performed PE on a 10-cm-thick wooden surface. Plasma creatine kinase (CK) activity, delayed onset muscle soreness (DOMS), knee range of motion (KROM), maximal isometric voluntary contraction (MIVC) of the knee extensors, vertical jump (VJ) and 10-m sprint were measured before and 24, 48 and 72 h after the PE. Compared to baseline values, FG showed significantly (p < 0.05) greater changes in CK, DOMS, and VJ at 24 until 48 h. The MIVC decreased significantly for the SG and FG at 24 until 48 h post-exercise in comparison to the pre-exercise values. There were no significant (p > 0.05) time or group by time interactions in KROM. In the 10-m sprint, all the treatment groups showed significant (p < 0.05) changes compared to pre-exercise values at 24 h, and there were no significant (p > 0.05) differences between groups. The results indicate that PE in an aquatic setting and on a sand surface induces less muscle damage than on a firm surface. Therefore, training in aquatic conditions and on sand may be beneficial for the improvement of performance, with a concurrently lower risk of muscle damage and soreness.

Quantitative Analysis of Urban Pluvial Flood Alleviation by Open Surface Water Systems in New Towns: Comparing Almere and Tianjin Eco-City

Increased surface runoff generated in urban areas due to larger proportion of impervious surfaces has, in many cases, exceeded the capacity of urban drainage systems. In response to such challenge, this paper introduces the quantitative analysis of pluvial flood alleviation by open surface water systems in the case of Almere in the Netherlands and compares it with Tianjin Eco-City in China, with the aim of optimizing land use planning and urban design for new urban districts. The methodology is a combination of quantitative and qualitative analysis. With the analytical tool of ArcGIS, the authors have investigated the influence of spatial distribution of surface water system on the reduction of pluvial flood risks. The conclusions include some preliminary principles: (1) a densely distributed surface water network is preferable; (2) areas farther away from water body require water sensitive spatial intervention; and (3) optimizing the allocation of different types of ground surface could contribute to pluvial flood alleviation. An alternative design proposal for a typical urban block in Tianjin Eco-City has been put forward to illustrate these principles.

Effects of visibility and types of the ground surface on the muscle activities of the vastus medialis oblique and vastus lateralis.

[Purpose] The purpose of this study was to compare the effects of visibility and types of ground surface (stable and unstable) during the performance of squats on the muscle activities of the vastus medialis oblique (VMO) and vastus lateralis (VL). [Subjects and Methods] The subjects were 25 healthy adults in their 20s. They performed squats under four conditions: stable ground surface (SGS) with vision-allowed; unstable ground surface (UGS) with vision-allowed; SGS with vision-blocked; and UGS with vision-blocked. The different conditions were performed on different days. Surface electromyogram (EMG) values were recorded. [Results] The most significant difference in the activity of the VMO and VL was observed when the subjects performed squats on the UGS, with their vision blocked. [Conclusion] For the selective activation of the VMO, performing squats on an UGS was effective, and it was more effective when subjects’ vision was blocked.

Gait characteristics of children with cerebral palsy as they walk with body weight unloading on a treadmill and over the ground.

Body weight support (BWS) has become a typical strategy for gait training, in special with children with cerebral palsy (CP). Although several findings have been reported in the literature, it remains uncertain how different types of surfaces and gradual amount of BWS can facilitate the mobility of children with CP. The aim of this study was to investigate gait kinematic parameters of children with CP by manipulating BWS and two different types of ground surfaces. Ten children (7.7 ± 2.1 years old) diagnosed with spastic CP and GMFCS classification between levels II and IV were asked to walk on a treadmill and over the ground. In both conditions, BWS was manipulated to minimize gravitational effects and spatial-temporal gait parameters and lower limb joints were analyzed. The results revealed that the type of ground surface causes greater impact on the gait pattern of children with CP as compared to body weight unloading. This finding may provide new insights into the behavioral heterogeneity of children with CP, and offers critical information to be considered on interventional programs specifically designed to improve mobility on this population.

Experimental Study of the Applicability of the Remotely Positioned Laser Doppler Vibrometer to Rock-Block Stability Assessment

This paper examines a new method for evaluating the stability of rock blocks on slopes using a remotely positioned Laser Doppler Vibrometer (LDV). A series of experiments using physical models were conducted to evaluate the validity of this new method. Based on the experimental studies, the applicability of LDV was examined by comparing results with a conventional seismometer measurement. To examine the quantitative correlations between vibration properties and the stability of a rock block, the effects on the vibration properties of the size of the rock block, the initial block position, the slope incline, and the type of ground surface were studied. The experimental results showed that LDV measurements agreed with conventional seismometer measurements. There was also a good correlation between vibration properties and rock-block stability. On the other hand, it was found that for a boulder on tightly compacted ground, the application of block stability assessment by tonometry was difficult when measuring microtremors or sloppy vibration due to nearby vehicle traffic. Furthermore, numerical analysis of the slope model was carried out to examine the validity of the model experiment and application of the suggested technique. The results of the analysis demonstrated that the suggested technique was effective for application to stability monitoring of a block and evaluation of the effect of stability measures.

Estimation of infiltration and surface run-off characteristics of radionuclides from gamma dose rate change after rain

A method to estimate the infiltration and surface run-off characteristics of radionuclides on three types of ground surface from gamma dose rate change due to rain has been developed. We proposed the estimation methods based on the differences in the dose rate increases between monitoring stations caused by different attenuation of gamma ray due to infiltration and by the different run-off characteristics. The gamma dose rate data used for the estimation were measured at near-by monitoring stations in which the ground type around the detector differed from each other. Rain events were selected by the criteria in which 214Pb and 214Bi deposition amounts are considered to be uniform with in the area in which objective monitoring stations are deployed. We also calculated the surface concentration considering both infiltration and surface run-off processes. As a result, it was shown that the calculated surface concentration was about 40% larger than that considering neither processes of the infiltration and surface run-off.

Modeling of the fate of radionuclides in urban sewer systems after contamination due to nuclear or radiological incidents

After an accidental radioactive contamination by aerosols in inhabited areas, the radiation exposure to man is determined by complex interactions between different factors such as dry or wet deposition, different types of ground surfaces, chemical properties of the radionuclides involved and building development as well as dependence on bomb construction e.g. design and geometry. At short-term, the first rainfall is an important way of natural decontamination: deposited radionuclides are washed off from surfaces and in urban areas the resulting contaminated runoff enters the sewer system and is collected in a sewage plant. Up to now the potential exposure caused by this process has received little attention and is estimated here with simulation models. The commercial rainfall-runoff model for urban sewer systems KANAL++ has been extended to include transport of radionuclides from surfaces through the drainage to various discharge facilities. The flow from surfaces is modeled by unit hydrographs, which produce boundary conditions for a system of 1d coupled flow and transport equations in a tube system. Initial conditions are provided by a map of surface contamination which is produced by geo-statistical interpolation of γ-dose rate measurements taking into account the detector environment. The corresponding methodology is implemented in the Inhabited Area Monitoring Module (IAMM) software module as part of the European decision system JRODOS. A hypothetical scenario is considered where a Radiation Dispersal Device (RDD) with Cs-137 is detonated in a small inhabited area whose drainage system is realistically modeled. The transition of deposited radionuclides due to rainfall into the surface runoff is accounted for by different nuclide-specific entrainment coefficients for paved and unpaved surfaces. The concentration of Cs-137 in water is calculated at the nodes of the drainage system and at the sewage treatment plant. The external exposure to staff of the treatment plant is estimated. For Cs-137 radiation levels in the plant are low since wash-off of cesium from surfaces is an ineffective process.