Considerations regarding Motorcycle Adaptation as a Power Source for Agriculture

The terrain slope is a real-world feature. In this study, the effect of a slight terrain slope on the flow structure is studied in connection with the problem of the urban heat island by a proposed two-length scale κ-e model. Findings indicate that even a slight slope can cause appreciable change in the flow structure. The degree of alteration depends on both the slope and the temperature difference between the rural and urban area

Skid-steered robots are commonly used in outdoor applications due to their mechanical simplicity, high maneuverability, and robustness. The maneuverability of these robots allows them, under ideal conditions (e.g., flat terrain and powerful actuators), to perform turning maneuvers ranging from point turns to straight line motion. However, sloped terrain, terrain with high friction, or actuator torque and power limitations can limit the achievable turning radii. This work presents the analysis and experimental verification of a dynamic model for skid-steered autonomous ground vehicles equipped with non ideal (i.e., torque and power limited) actuators and moving on sloped terrains. The experimental results show that the model is able to predict motor torques for the full range of turning radii on flat ground, i.e., from point turns to straight line motion. In addition, it is shown that the proposed model is able to predict motor torques (including motor saturation) and minimum turn radius as a function of terrain slope, vehicle heading, terrain parameters and actuator characteristics. This makes the model usable for curvilinear motion planning tasks on sloped surfaces.© 2012 ASME

Application of Reynolds-stress model to the study of heat island structure over a slightly inclined terrain

Application of Reynolds-stress model to the study of heat island structure over a slightly inclined terrain

Application of Reynolds-Stress Model to the Study of Heat Island Structure over a Slightly Inclined Terrain

The timber frame on sloped terrain (TFS) features varying column base heights and inconsistent lateral stiffness, making its lateral performance vital for the stability of timber structures in mountainous areas. This study employed both test and simulation methods to investigate the lateral performance of TFS. Pseudo-static tests were conducted to assess the deformation and bearing capacity of TFS under lateral forces. The Open System for Earthquake Engineering Simulation (OpenSees) was used to model the beams, columns, and joints. A finite element model (FEM) of the TFS was then developed and validated against test results. Additionally, factors such as upper ground height and number of layers of the frame were analyzed. The results showed that the lateral behavior of traditional timber frames can be effectively simulated using OpenSees. The upward shift of the contraflexure point in TFS suggests that these structures are more susceptible to collapse than frames on flat terrain. As the height of the upper ground end increases, the stiffness and bearing capacity of the TFS, as well as the forces on the mortise-tenon joints and column feet, also increase. Conversely, as the number of layers increases, the frame stiffness decreases, while peak displacement and bearing capacity rise.

Past work has shown that coupling can exist between atmospheric air flows at street scale (O(0.1 km)) and city scale (O(10 km)). It is generally impractical at present to develop high-fidelity urban simulations capable of capturing such effects. This limitation imposes a need to develop better parameterisations for meso-scale models but an information gap exists in that past work has generally focused on simplified urban geometries and assumed the buildings to be on flat ground. This study aimed to begin to address this gap in a systematic way by using the large eddy simulation method with synthetic turbulence inflow boundary conditions to simulate atmospheric air flows over the University of Southampton campus. Both flat and realistic terrains were simulated, including significant local terrain features, such as two valleys with a width about 50 m and a depth about average building height, and a step change of urban roughness height. The numerical data were processed to obtain averaged vertical profiles of time-averaged velocities and second order turbulence statistics. The flat terrain simulation was validated against high resolution particle image velocimetry data, and the impact of uncertainty in defining the turbulence intensity in the synthetic inflow method was assessed. The ratio between realistic and flat terrains of time-mean streamwise velocity at the same ground level height over a terrain crest location can be >2, while over a valley trough it can be <0.5. Further data analysis conclusively showed that the realistic terrain can have a considerable effect on global quantities, such as the depth of the spanwise-averaged internal boundary layer and spatially-averaged turbulent kinetic energy. These highlight the potential impact that local terrain features (O(0.1 km)) may have on near-field dispersion and the urban micro-climate.

The goal of this study was to evaluate the reliability of the HOBO Pendant G Accelerometer Datalogger (Onset Computer Corporation, Bourne, Massachusetts, USA) in measuring standing and lying behavior of yearling bulls in a pen with both flat and sloped terrain. The study was conducted with 6 focal bulls selected from a pen of 26 Angus bulls. Data were collected during two separate 2-week sessions (4 weeks total). During this period, the accelerometers recorded leg orientation in the y-axis at 1-minute intervals to determine time spent standing and lying. To validate the accelerometer data, 35 in-person observational sessions were conducted. Each live observation focused on one individual bull. Trained observers noted whether the bull was standing or lying as well as the bull’s location in the pen (on hill or flat terrain) using 1-minute scan sample intervals for 3 hours. Data analysis was conducted using RStudio (R version 3.6.0). Spearman correlation tests were performed to compare the observed standing behavior to the accelerometer data. The correlations were calculated for the entire dataset as well as for individual terrain types (flat and hill). The correlation coefficient (r) between observed standing time and accelerometer standing time was 0.92 for all observations, indicating a strong positive relationship. For the analysis of standing behavior on the hill, the correlation increased to r = 0.95, and on the flat terrain, it remained similarly high at r = 0.92. These results demonstrate that the Hobo Pendant G Acceleration Dataloggers are reliable for tracking standing and lying behavior in a pen with varying terrain types.

The forest inventory plays a crucial role in forest management planning, and it is the first step in planning actions for forest production. However, conducting an inventory can be expensive and complex. Forest inventory applications on smartphones have emerged as an alternative to traditional methods and they aim to make field data collection more accessible to non-professionals while ensuring accuracy in determining the volume of wood in a given area. This study evaluates the effectiveness of the Katam, Arboreal, and Trestima applications compared to traditional data collection methods. The study focuses on assessing the stand density and diameter of sampled trees—two key variables that are assessed in forest inventories. Two species, maritime pine (Pinus pinaster Aiton) and Eucalyptus spp. (mainly Eucalyptus globulus and Eucalyptus nitens), were used to evaluate the performance of the methods, with assessments performed in the stands of diverse dendrometric characteristics, specifically those regarding the tree age, stand density, and topographic conditions (flat or sloping terrain). For the purpose of comparison, goodness-of-fit statistics (R2, RMSE, and BIAS) were calculated, and an analysis of the diameter distribution and comparison of the mean diameter, number of trees per hectare, and basal area were performed. In general, the applications were accurate, and the average basal area did not differ significantly from the traditional method. The diameter measurements showed good accuracy. The accuracy of the applications varied depending on the terrain and forest characteristics, with the applications performing better in areas with flat terrain, as well as with older forests that were regular and had low under-cover density. In contrast, the applications performed worse in younger, irregular forests with sloping terrain, high tree density, and those with a great deal of understory vegetation. The applications still need to evolve in evaluating other important variables (such as tree height or volume) as they are currently estimated from auxiliary variables through mathematical equations.

Three electromagnetic models are employed for the investigation of ultrawideband VHF scattering from tree trunks situated over flat and sloped terrain. Two of the models are numerical, each employing a frequency-domain integral-equation formulation solved via the method of moments (MoM). A body-of-revolution (BoR) Mote formulation is applied for a tree trunk on a flat terrain, implying that the BoR axis is perpendicular to the layers of an arbitrary layered-earth model. For the case of sloped terrain, the BoR model is inapplicable, and therefore the MoM solution is performed via general triangular-patch basis functions. Both MoM models are very accurate but are computationally expensive. Consequently, the authors also consider a third model, employing approximations based on the closed-form solution for scattering from an infinite dielectric cylinder in free space. The third model is highly efficient computationally and, despite the significant approximations, often yields accurate results relative to data computed via the reference MoM solutions. Data from the three models are considered, and several examples of application to remote sensing are addressed.

This study aimed to model and identify the most productive cutting methods of tree plantations by comparing a forward felling technique (C) with sideways techniques outside (A and D) or inside cutting edge (B and E). Drone video material of each tree was analyzed by comparing time distribution of work phases. The relation between this input data and harvester production data was analyzed by regression models. A quadratic model predicted productivity precisely (R2 = 0.95) and explained the effective-hour productivity in cutting cycle with dummy variables of harvesting conditions. The productivity was explained by tree size and cutting cycle time, while effects of operator and harvester were eliminated by statistical analysis. In loblolly pine (Pinus taeda L.) plantations on flat terrain, cutting method B was 4.8 m3/E0h (effective working hour) more productive than method A, and 6.7 m3/E0h than method C. In Sydney blue gum (Eucalyptus saligna Sm.) plantations, cutting method E was 1.8 m3/E0h more productive than cutting method D on sloping terrain. Of the time-cycle variables, time consumption of the “moving of tree” changed significantly between the cutting methods, of which the ones that used the sideways felling technique inside cutting edge were most efficient. This quadratic modeling structure can be recommended for precise studies in similar harvesting conditions.Graphical

&amp;lt;p&amp;gt;Impact ejecta flows are found on rocky planets, and some icy moons. In contrast to ballistically emplaced ejecta, which thins exponentially from crater rims, ejecta flow deposits have a layered morphology with steeper margins, often lobate in shape. This fluidised morphology is thought to result from deposition by ground-hugging flows. For ejecta flows on Mars, the Earth, and some icy satellites, volatiles have been suggested as a possible fluidising agent. Ejecta flows on the Moon however, where volatiles are mostly absent, are likely dry granular flows.&amp;lt;/p&amp;gt; &amp;lt;p&amp;gt;On Mercury, seven ejecta flow deposits were reported by Xiao and Komatsu (2013), described as single layer deposits, extending downslope into adjacent, older craters (Fig 1A). These flows could have occurred during the impact process, or afterwards by mass-wasting. Hokusai crater also has an apparent ejecta flow (Barnouin et al., 2015), but by contrast it occurs on relatively flat ground and does not extend into an adjacent crater (Fig 2A).&amp;lt;/p&amp;gt; &amp;lt;p&amp;gt;&amp;lt;img src=&amp;quot;&amp;quot; alt=&amp;quot;&amp;quot; /&amp;gt;&amp;lt;/p&amp;gt; &amp;lt;p&amp;gt;Figure 1: Previously reported ejecta flows on Mercury. Image A = Unnamed crater with an ejecta flow extending downslope into an adjacent crater. Reported by Xiao and Komatsu (2013). Image B = Hokusai crater with an ejecta flow on flat ground. Reported by Barnouin et al. (2015). Red arrows indicate flow boundaries.&amp;lt;/p&amp;gt; &amp;lt;p&amp;gt;Here we present a global survey of Mercury identifying 36 craters with ejecta flows and a further 27 probable examples (Fig 2). The majority occur around craters ~30&amp;amp;#8211;80 km in diameter and are widespread across the planet. All but two of the ejecta flows appear to extend downslope into adjacent craters or other topographic lows. In addition to Hokusai, an unnamed crater, also on the northern plains, has an ejecta flow on relatively flat ground (&amp;lt;2&amp;amp;#176; slope) and not extending into an adjacent crater (Fig 3). These two flows look distinct from other examples on Mercury, resembling single-layer ejecta craters on Mars, with distal ramparts and a ropey texture. The prevalence of Mercurian ejecta flows shown by this survey is also of note, representing at least a fourfold increase in the number of known flows.&amp;lt;/p&amp;gt; &amp;lt;p&amp;gt;&amp;lt;img src=&amp;quot;&amp;quot; alt=&amp;quot;&amp;quot; /&amp;gt;&amp;lt;/p&amp;gt; &amp;lt;p&amp;gt;Figure 2: Results of a global survey for ejecta flows. Purple triangles = Previously reported flows. Yellow squares = Flows identified by this survey. Green circles = Probable flows identified by this survey. Image is a monochromatic basemap of Mercury in a simple cylindrical projection. The middle of the image is at 0 degrees longitude, with Mercury quadrangle boundaries shown in red.&amp;lt;/p&amp;gt; &amp;lt;p&amp;gt;&amp;lt;img src=&amp;quot;&amp;quot; alt=&amp;quot;&amp;quot; /&amp;gt;&amp;lt;/p&amp;gt; &amp;lt;p&amp;gt;Figure 3: Unnamed crater with an ejecta flow on flat ground. Distal ramparts at flow boundaries indicated with red arrows.&amp;lt;/p&amp;gt; &amp;lt;p&amp;gt;As Mercury has volatile-bearing materials at the surface, these could be a factor in ejecta fluidisation. However, we find no evidence for volatile involvement, and features indicative of local volatile concentration (e.g. hollows) don&amp;amp;#8217;t occur preferentially near to ejecta flows. Slope of local terrain is clearly a major factor in influencing ejecta flow development on Mercury, since almost all flows extend downslope into adjacent craters. Perhaps some flows are post-impact mass movements, rather than forming during the impact process. However, other work shows that for at least one example, the time of emplacement was contemporaneous with impact (Lennox et al., 2022).&amp;lt;/p&amp;gt; &amp;lt;p&amp;gt;Of the flows on low slopes, Hokusai crater exhibits evidence of excess impact melt: a possible fluidising agent (Barnouin et al., 2015). However, the other crater with a flow on relatively flat ground has no identifiable impact melt present outside the crater rim. The crater is also considerably smaller than Hokusai (~37 km vs 95 km diameter), and smaller craters tend to have proportionally less impact melt. Understanding how this crater&amp;amp;#8217;s ejecta flow formed would give insight into the factors influencing ejecta fluidisation on Mercury, as for this crater the slope of local terrain, volatile presence, and impact melt excess do not appear to be obvious factors.&amp;lt;/p&amp;gt;

Walking aid robots have been developed for elderly people or patients facing difficulties while walking. However, most of them are designed only for flat ground, must rely on handles, and have drawbacks such as oscillation and lack of stability. The primary goal of this research is to improve the transparency and safety of a walking aid robot, addressing both flat and sloping terrains. To achieve this goal, we propose a novel variable admittance control strategy for an omnidirectional mobile platform by combining human motion recognition and a slope-adaptive approach. We design a vision system with a wide-angle camera to capture skeletal whole-body information at a close distance to recognize the walking direction. Accordingly, the damping values of the admittance controller are varied. In addition, these parameters are varied with respect to the slope angle of the ground, which is detected by the platform. We validated the controller performance with eleven healthy subjects performing two experiments on both flat and sloping terrains. Three admittance controllers are compared, with fixed parameters, variable damping by Cartesian velocity, and variable damping by walking direction. Experimental results show the advantages of the variable admittance control based on walking direction, which ensures high transparency and smoothness on both flat and sloping terrains.

In a Lagos lecture on ‘Nigeria in World Affairs’ in the mid-1970s, Ali Mazrui predicted that at the end of this century Nigeria would have greater diplomatic influence than either Britain or France even though she might not be as technologically developed as them [1]. Mazrui’s prediction must be regarded as too bold and perhaps misleading. Bold because a variety of factors, and the forces of the unforeseen, could frustrate this prediction. Misleading because it tends to separate the level of industrial technology from the diplomatic weight of a country. While it is arguable that diplomatic influence does not necessarily correspond to the level of technological development, it is also true that a country with a low level of technological and industrial development can hardly have much diplomatic weight.

Bu çalışma Yenişarbademli Yöresi’nde önemli bir asli orman ağacı türümüz olan Karaçam’ın verimliliği ve dağılımı ile yetişme ortamı özellikleri arasındaki ilişkileri ekolojik anlamda ortaya koyabilmek amacıyla gerçekleştirilmiştir. Çalışmaya ait veriler, yörede karaçam türünün doğal olarak bulunduğu alanlardan seçilen 70 örnek alandan elde edilmiştir. Karaçamın verimliliği ile yetişme ortamı özellikleri arasındaki ikili ilişkiler Pearson ve Spearman korelasyon analizleri ile irdelenmiştir. Türün verimliliğinin modellenmesi aşamasında çoklu regresyon analizinden faydalanılmıştır. Korelasyon analizleri sonucunda yükselti, alt yamaç ve düz arazi değişkenleri ile pozitif, eğim ve engebelilik değişkenleri ile negatif yönde ilişkiler belirlenmiştir. Modelleme aşamasında korelasyon analizlerinde olduğu gibi türe ait verimlilik modelini yükselti, alt yamaç ve düz arazi değişkenlerinin oluşturduğu sonucuna ulaşılmıştır.Çalışmadan elde edilen sonuçlar, başta Yenişarbademli yöresi ormanlık alanları olmak üzere tüm ülke ve dünya ölçeğinde karaçam türüne ait yapılacak ekolojik çalışmalara, gelecekte yapılacak ağaçlandırma ve koruma planlarının uygulanmasına katkı sağlayacaktır