Displacement Monitoring Using GPS at an Unstable Steep Slope and the Performance of a New Low-Cost GPS Sensor

Author(s):  
Nguyen Trung Kien ◽  
Shinichiro Nakashima ◽  
Norikazu Shimizu
2020 ◽  
Author(s):  
Paolo Tarolli ◽  
Eugenio Straffelini ◽  
Chiara Maria Mattiello ◽  
Aldo Lorenzoni

<p>Cultivating in high-steep slope hilly and mountainous landscapes, requires a great effort in terms of economic and human resources, especially if the territory is particularly complex from a geomorphological point of view and historically affected by landslides such as the Italian peninsula. This fragility is also combined with two other factors. The first is linked to agricultural mechanization, which causes soil compaction and a consequent alteration of its draining capacity. The second is related to climate change, responsible for an increase of extreme rainfall events characterized by intense, shorter and localized precipitations. The combination of these elements makes agricultural terraced landscapes at risk and prestigious vineyards, particularly important for historical, cultural, landscaping and economic reasons, increasingly sensitive to soil erosion processes.</p><p>In response to these problems, the project SOiLUTION SYSTEM is proposed (www.soilutionsystem.com),  aiming to identify an integrated system of environmentally and economically sustainable interventions able to reduce the risk of erosion and improve soil management in the terraced area of Soave (Veneto region), one of the two Italian GHIAS-FAO site. Indeed, in such terraced areas, the hydrogeological risk is high due to the steep-slope where heroic vineyards are cultivated. The project is also focused on multidisciplinary, capable of combining expertise from the academic world, farmers and other stakeholders, in order to promote a sustainable production approach to ensure greater soil resilience, as well as to protect biodiversity.</p><p>In the first phase, several terraced study areas historically threatened by erosion have been selected. Within them were organized topographic surveys using a low-cost commercial drone in combination with an RTK-GPS for the 3D reconstruction of the terrain using the Structure-From-Motion photogrammetric technique. The point cloud obtained was subsequently processed, filtered and interpolated in order to create high-resolution digital terrain models (DTM) with cells of resolution less than 50cm. Based on the obtained data, some geomorphological indicators were calculated to identify areas potentially susceptible to erosion. In order then to understand the processes that take place at a larger scale than the single areas detected by drone, geomorphological analyses were also performed on a 1m DTM elaborated from airborne LIDAR data, granted by the Italian Ministry for Environment, Land and Sea (MATTM).</p><p>The goals of the project are 1) to provide innovative survey techniques using low-cost commercial drone to better understand erosion processes in vineyards; 2) to install innovative tools for the monitoring of surface runoff in the field; 3) to test new mechanization prototypes with low impact on the soil and able to work on steep slopes; 4) to provide an innovative technique for the consolidation of dry stone walls; 5) to introduce the “conservative agriculture” for improving soil management; 6) to analyze the role of native herbaceous species as grass cover in erosion reduction; 7) to evaluate the efficiency of the proposed management model in considering biodiversity conservation purposes.</p>


2019 ◽  
Vol 22 (15) ◽  
pp. 3319-3327
Author(s):  
Peng Liu ◽  
Chengcheng Liu ◽  
Lixiao Zhang ◽  
Xuefeng Zhao

Currently, laser technology has become increasingly mature. Semiconductor lasers have the characteristics of small size, long indication distance, long life, and low cost. Therefore, many studies regard them as the launching devices of monitoring system and fix them at the monitoring points of structures to reflect the displacements of the monitoring points through the spots produced by them. However, this method also exhibits a drawback, that is, this method can only be applied to the case where only displacement is generated at the monitoring point and no rotation angle is generated. If the rotation occurs at the monitoring point, the spot displacement is caused by the coupling effect of the displacement and rotation angle at the monitoring point, which will affect the monitoring results significantly. In this article, a method is proposed to decouple the effect of the displacement and angle and eliminate the influence of the angle sufficiently, by projecting the laser spots onto two screens. This method can significantly improve the application scope of the monitoring system and provide the possibility for its application in practical engineering.


2020 ◽  
Vol 12 (1) ◽  
pp. 9
Author(s):  
Jiajia Wang ◽  
Guangming Li

Bridge displacement measurement is an important area of bridge health monitoring, which can directly reflect whether the deformation of bridge structure exceeds its safety permission. Target tracking technology and Digital Image Correlation (DIC) are two fast-developing and well-known methods for non-contact bridge displacement monitoring in Digital Image Processing (DIP) methods. The former’s cost of erecting detection equipment is too large for bridges with a large span that need to locate more multi-targets because of its tracking only one target on a camera while the latter is not suitable for remote detection because it requires very high detection conditions. After investigating the evolution of bridge displacement monitoring, this paper proposes a bridge displacement monitoring algorithm based on multi-target tracking. The algorithm takes full account of practical application and realizes accuracy, robustness, real-time, low-cost, simplicity, and self-adaptability, which sufficiently adapts the bridge displacement monitoring in theory.


2012 ◽  
Vol 20 (9) ◽  
pp. 1240-1254 ◽  
Author(s):  
Hongki Jo ◽  
Sung-Han Sim ◽  
Andrzej Tatkowski ◽  
B. F. Spencer ◽  
Mark E. Nelson

Author(s):  
Y. L. Chen ◽  
S. Fujlshiro

Metastable beta titanium alloys have been known to have numerous advantages such as cold formability, high strength, good fracture resistance, deep hardenability, and cost effectiveness. Very high strength is obtainable by precipitation of the hexagonal alpha phase in a bcc beta matrix in these alloys. Precipitation hardening in the metastable beta alloys may also result from the formation of transition phases such as omega phase. Ti-15-3 (Ti-15V- 3Cr-3Al-3Sn) has been developed recently by TIMET and USAF for low cost sheet metal applications. The purpose of the present study was to examine the aging characteristics in this alloy.The composition of the as-received material is: 14.7 V, 3.14 Cr, 3.05 Al, 2.26 Sn, and 0.145 Fe. The beta transus temperature as determined by optical metallographic method was about 770°C. Specimen coupons were prepared from a mill-annealed 1.2 mm thick sheet, and solution treated at 827°C for 2 hr in argon, then water quenched. Aging was also done in argon at temperatures ranging from 316 to 616°C for various times.


Author(s):  
J. D. Muzzy ◽  
R. D. Hester ◽  
J. L. Hubbard

Polyethylene is one of the most important plastics produced today because of its good physical properties, ease of fabrication and low cost. Studies to improve the properties of polyethylene are leading to an understanding of its crystalline morphology. Polyethylene crystallized by evaporation from dilute solutions consists of thin crystals called lamellae. The polyethylene molecules are parallel to the thickness of the lamellae and are folded since the thickness of the lamellae is much less than the molecular length. This lamellar texture persists in less perfect form in polyethylene crystallized from the melt.Morphological studies of melt crystallized polyethylene have been limited due to the difficulty of isolating the microstructure from the bulk specimen without destroying or deforming it.


Author(s):  
J. Temple Black

In ultramicrotomy, the two basic tool materials are glass and diamond. Glass because of its low cost and ease of manufacture of the knife itself is still widely used despite the superiority of diamond knives in many applications. Both kinds of knives produce plastic deformation in the microtomed section due to the nature of the cutting process and microscopic chips in the edge of the knife. Because glass has no well defined slip planes in its structure (it's an amorphous material), it is very strong and essentially never fails in compression. However, surface flaws produce stress concentrations which reduce the strength of glass to 10,000 to 20,000 psi from its theoretical or flaw free values of 1 to 2 million psi. While the microchips in the edge of the glass or diamond knife are generally too small to be observed in the SEM, the second common type of defect can be identified. This is the striations (also termed the check marks or feathers) which are always present over the entire edge of a glass knife regardless of whether or not they are visable under optical inspection. These steps in the cutting edge can be observed in the SEM by proper preparation of carefully broken knives and orientation of the knife, with respect to the scanning beam.


Sign in / Sign up

Export Citation Format

Share Document