Explore the vast range of titles available.

On the basis of the requirement to solve the operational safety of important construction and energy objects in the Czech Republic and further on the basis of acquired knowledge and experience in ensuring the measurement of shifts of construction objects, the Geodetic, Topographic and Cartographic Research Institute in the Czech Republic, v.v.i. proceeded with the development of a sensor for measuring height shifts and its integration into an integrated measuring system. As part of the project BIM - Building Management II - development of IoT modular blocks for the digital twin of the building, co-financed by the European Union, a sensor based on hydrostatic levelling was developed with an accuracy of measuring height shifts of 0.1 mm, with a measuring range of up to 2.5 m between individual measuring sensors and with the possibility of its inclusion in an integrated measuring system. This contribution gives technical details about the developed sensor.

Barometric levelling, traditionally employed in aviation, parachute jumping, and mountain climbing, has undergone a transformative shift with the technological advancement of state-of-the-art atmospheric pressure sensors. This evolution has rendered these sensors more accurate and affordable, broadening their applications within the realm of Intelligent Systems. The integration of barometric altimeter modules into electronic devices, coupled with GNSS and mapping systems, has significantly enhanced their versatility, making them complementary components in various consumer electronics like smartphones, watches, sports bands, bicycle computers, and motor vehicle tracking devices. Moreover, they play a pivotal role in emerging technologies such as drone mapping projects and modelling. This because of their capabilities of measuring elevations in GNSS denied areas such as caves, canyons, and tunnels. The significance of barometric levelling lies in its capacity to determine relative elevation between two points through the measurement of atmospheric pressure. This technique leverages the fact that atmospheric pressure decreases with increasing altitude, enabling the calculation of elevation differences by comparing pressure readings at different locations.In this study, 25 elevations within a 3 km radius were independently measured using barometric levelling, highlighting its practical usage. These elevations ranged from 2 m to 140 m. Readings of time of measurements, temperature, air pressure, and humidity were taken at each of these stations and were synchronized with the readings obtained from a fixed reference station of known elevation. The measurements at this reference station were carried out with an instrument with data logging capabilities, able to record relevant weather data at pre-established intervals of time without human intervention. The results of these measurements were compared to fixed reference stations of known elevation, and the subsequent differences were analysed. The study employed a portable weather monitoring instrumentation with data logging capabilities, emphasizing the importance of automated data collection practices. The comparison of the 25 elevation readings with true elevations, determined by conventional surveying methods, revealed an RMSE of +/- 0.49 meters, affirming the accuracy of barometric levelling.Additionally, a distance-dependent test demonstrated a predictable decrease in positional accuracy as the distance from a reference base station increased, providing valuable insights into the system's limitations. The barometric levelling tests presented here offer results that can inform future applications. The conclusions and recommendations derived from this study provide guidance for optimizing the use of barometric levelling within the broader landscape of Intelligent Systems.

Despite the significance of resource levelling, project managers lack various ways to smooth resource usage fluctuation of a repetitive construction project besides changing resource usage. Tolerating interruptions is an effective way to provide flexibility for a schedule but is ignored when solving resource levelling problems. Therefore, this paper investigates the impacts of interruptions on resource usage fluctuation and develops an integrated approach that simultaneously integrates two scheduling adjusting processes: changing resource usage and tolerating interruptions. In this paper, two interruption conditions are proposed to identify which activities are suitable to be interrupted for smoothing resource usage fluctuation. The traditional resource levelling model is modified to a new scheduling model by incorporating interruptions. A two-stage GA-based scheduling algorithm is developed by integrating changing resource usage and tolerating interruptions. A commonly used pipeline project is adopted to illustrate the steps of the proposed approach and demonstrate its effectiveness and superiority through comparison with previous studies. A large-scale project further verifies the usability of the proposed approach. The results confirmed the feasibility to smooth resource usage fluctuation by interruptions, and the integrated approach can achieve a more competitive resource levelling result.

Background Finite element model updating (FEMU) is an inverse technique that is used to identify material (constitutive) model parameters based on experimental data. These experimental data, often in the form of full-field strains, may be subject to a filtering bias unique to the measurement technique, which can propagate to material parameter identification error. Objective Numerically adjusting for this filtering mismatch between the finite element analysis (FEA) and experimental measurements, here from Digital Image Correlation (DIC), is necessary to produce an accurate calibration. We investigate “direct-leveling” the FEA to the DIC data, i.e. computing strains using consistent methods and length scales for both data sets, before performing model calibration. Thus, both data sets have the same spatial resolution and can be quantitatively compared more readily. Methods We generated two sets of synthetic “experimental” DIC displacement data: one directly from FEA nodal displacements and one from DIC images synthetically deformed according to the FEA displacements. We then explored how the FEMU material model parameter identification is affected by DIC user-defined settings, including virtual strain gauge size, step size, and subset shape function, as well as misalignment between the FEA and DIC datasets. Results We found that direct-levelling of the FEA data before FEMU calibration returned more accurate results. This accuracy was independent of the DIC settings and spatial resolution. In contrast, performing FEMU with the unlevelled FEA data resulted in significant biases in the identified parameters. Conclusion In FEMU-based calibrations, it is advantageous to properly level the strain from the FEA to match the filtering and spatial resolution of the DIC results.

Surface subsidence above salt mines reflects the complex interaction of elastic and viscous deformation processes in rock salt, as well as hydrogeological and structural changes within diapiric formations. This study evaluates long-term ground movements above two Polish salt diapirs: Wapno, affected by catastrophic flooding in 1977, and Kłodawa, where mining continues in selected panels. High-precision levelling records collected over several decades were analysed to determine subsidence magnitude, trough geometry and time-dependent deformation behaviour. In Wapno, suffosion and dissolution caused extensive discontinuous failures, whereas in Kłodawa, deformation remains primarily continuous and controlled by chamber convergence. By introducing and applying the concept of observational capacity, the research highlights the necessity of maintaining geodetic monitoring networks capable of capturing evolving deformation fields. The findings support the implementation of sustained levelling campaigns to ensure infrastructure safety, validate geomechanical models and enhance land-use planning in salt-mining regions.

Small landholders can implement a range of climate-smart agricultural (CSA) practices and technologies, in order to minimize the adverse effects of climate change and variability, but their adoption largely depends on economic benefits associated with the practices. To demonstrate the potential economic benefits of CSA practices, we conducted a study with smallholder farmers in the Indo-Gangetic Plains (IGP) of India. Among the CSA practices and technologies including use of improved crop varieties, laser land levelling, zero tillage, residue management, site specific nutrient management, and crop diversification, a majority of the farmers prefer to use improved crop varieties, crop diversification, laser land levelling and zero tillage practice. We estimated the cost of adoption, change in yields and income for the implementation of three major CSA practices in rice–wheat system. The average cost of adoption were +1,402, +3,037 and –1,577 INR ha–1 for the use of improved crop varieties, laser land levelling and zero tillage respectively. Results show that farmers can increase net return of INR 15,712 ha–1 yr–1 with improved crop varieties, INR 8,119 ha–1 yr–1 with laser levelling and INR 6,951 ha–1 yr–1 with zero tillage in rice–wheat system. Results also show that the combination of improved seeds with zero tillage and laser land levelling technologies can further improve crop yields as well as net returns. The econometric analysis indicates that implementations of CSA practices and technologies in smallholder farms in the IGP of India, have significant impacts on change in total production costs and yield in rice–wheat system.

Real-time geopotential measurements with two synchronously linked optical lattice clocks are demonstrated. A height difference between the two clocks separated by 15 km is determined, with an uncertainty of 5 cm, by means of a gravitational redshift. According to Einstein's theory of relativity, the passage of time changes in a gravitational field 1 , 2 . On Earth, raising a clock by 1 cm increases its apparent tick rate by 1.1 parts in 10 18 , allowing chronometric levelling 3 through comparison of optical clocks 1 , 4 , 5 . Here, we demonstrate such geopotential measurements by determining the height difference of master and slave clocks separated by 15 km with an uncertainty of 5 cm. A subharmonic of the master clock laser is delivered through a telecom fibre 6 to synchronously operate 7 the distant clocks. Clocks operated under such phase coherence reject clock laser noise and facilitate proposals for linking clocks 8 , 9 and interferometers 10 . Taken over half a year, 11 measurements determine the fractional frequency difference between the two clocks to be 1,652.9(5.9) × 10 −18 , consistent with an independent measurement by levelling and gravimetry 11 . Our system demonstrates a building block for an internet of clocks, which may constitute ‘quantum benchmarks’, serving as height references with dynamic responses.

This paper discusses the relevance of the classical adjustment weights for the highestorder geometric levelling network. The commonly used weights are inversely proportional to the length of levelling lines. The argument behind this choice is the assumption that the accuracy of measured elevations is a function of the square root of the levelled route. Therefore, the longer the line, the less its weight in the adjustment of the network. However, there are often events where the measured elevations of long lines are more accurate than those of shorter ones. Thus, the classical weights do not correctly reflect the accuracy of the measured height differences and are a reason for incorrect final results and conclusions concerning the investigated processes by the adjusted network. Try to avoid this issue, we recommend weights that correspond to the actual line elevation accuracy. They are assumption-free weights regarding the factors that are supposed to form height differences uncertainty. Using the Jackknife procedure, we performed nnumber independent adjustments of the Bulgarian Second Levelling network /19531957/, where n is the number of levelling lines in the network. We skipped a different levelling line in each adjustment and calculated the averages of the produced standard errors of the adjusted benchmark heights. We used these averages to define the proposed line height difference weights. The comparison between samples of the standard errors of the adjusted benchmark heights, obtained by the proposed weights and the classical ones, shows that the former produce more accurate results than the latter. The conclusion is made at a significance level higher than 90%. Furthermore, the differences between the adjusted benchmark heights by both approaches, regarding some benchmarks, go beyond 20 mm. These differences are too much when considering the recent vertical movements in Bulgaria or establishing a state height reference system. We recommend including the proposed weighting method in the specifications for levelling data processing. Their usage can likely increase the state levelling network accuracy, but also explain a part of the mysterious systematic deteriorations of the state and continental reference systems.

We investigate using the GIRAFE cold-atom gravimeter during an airborne gravity survey for improving gravity field and quasigeoid modelling. The study is conducted over the Bay of Biscay, France. Geoid/quasigeoid determination is usually a major challenge over such coastal areas due to scarce and inconsistent gravity data. In a first step, the GIRAFE dataset is analysed and compared with available surface gravity data as well as with global altimetry models from UCSD and DTU. The comparisons indicate that the DTU model is better than the UCSD model within around 10 km from the coastline. Furthermore, recent satellite altimeter missions significantly improve the altimetry models in coastal areas. A significant bias (− 4.00 mGal) in shipborne data is also found from this comparison. In a second step, eight quasigeoid solutions are calculated to evaluate the contribution of GIRAFE data. This contribution reaches 3 cm in terms of height anomaly for DTU21 while being much larger for UCSDv31 and shipborne data. Finally, the quasigeoid solutions are validated using GNSS-levelling data. The results indicate that using GIRAFE data improves by approximately 50% the quality of quasigeoid models over land near the coast. The highest accuracy, around 1 cm, is achieved when GIRAFE data are merged with refined gravity data. Importantly, the standard deviation is just 1.2 cm when compared with GNSS-levelling points if using only GIRAFE data over marine areas, which is very close to the 1 cm goal of geoid/quasigeoid model determination in modern geodesy. This study thus confirms the benefits of performing airborne gravity survey using quantum sensors.

Abstract It has been shown that land fragmentation can negatively impact the efficiency of farming. Therefore, experts recommend land consolidation process, as a logical and workable solution to solve the problems and complications caused by land fragmentation. Land levelling and consolidation is a process of land reform that changes the construction of agricultural lands which leads to rural development through reforming farm management. However, a single plan cannot be applied to different regions, even though they might be in the same country. Hence, it is vital to investigate multiple factors in a certain region to devise the perfect consolidation plan. The present study, which is a survey-exploratory research, is conducted to provide a comprehensive model to implement the plan for levelling and consolidation of agricultural lands in the Abu Fazel region of Ahvaz, Iran. This research is an applied field research which uses both library and field methods to collect the required data. The study population is in Abu Fazel in the northeast of Ahvaz in Zargan region. The results of the study show that cultural, social, economic, policy-making, educational, agricultural and managerial factors have an effect on the participation of farmers in the levelling and consolidation of agricultural lands in the study area (p≥0.01). Also, there is a strong positive relationship between these factors and the farmers' participation in levelling and consolidation of agricultural lands (p≥0.01). Among these factors, it is observed that policy is main factor. Policymakers can play an effective role in land consolidation and macro development on the one hand and agricultural and rural development. On the other, by accurately assessing the interactive effect of land consolidation and related factors, along with the effects of this process on the evolution of agronomic systems. Resumo Tem sido demonstrado que a fragmentação da terra pode impactar negativamente a eficiência da agricultura. Portanto, os especialistas recomendam o processo de consolidação de terras como uma solução lógica e viável para resolver os problemas e as complicações causadas pela fragmentação de terras. O nivelamento e a consolidação da terra são processos de reforma agrária que alteram a construção de terras agrícolas, o que leva ao desenvolvimento rural por meio da reforma da gestão agrícola. No entanto, um único plano não pode ser aplicado a diferentes regiões, mesmo que estejam no mesmo país. Portanto, é vital investigar vários fatores em determinada região para elaborar o plano de consolidação perfeito. O presente estudo, que é uma pesquisa exploratória de levantamento, é realizado para fornecer um modelo abrangente para implementar o plano de nivelamento e consolidação de terras agrícolas na região de Abu Fazel, de Ahvaz, no Irã. Trata-se de uma pesquisa de campo aplicada que usa métodos de biblioteca e de campo para coletar os dados necessários. A população do estudo está em Abu Fazel, no nordeste de Ahvaz, na região de Zargan. Os resultados do estudo mostram que fatores culturais, sociais, econômicos, políticos, educacionais, agrícolas e gerenciais influenciam a participação dos agricultores no nivelamento e na consolidação das terras agrícolas na área de estudo (p ≥ 0,01). Além disso, há forte relação positiva entre esses fatores e a participação dos agricultores no nivelamento e na consolidação das terras agrícolas (p ≥ 0,01). Entre esses fatores, observa-se que a política é o principal deles. Os formuladores de políticas, por um lado, podem desempenhar um papel efetivo na consolidação da terra e no macrodesenvolvimento e desenvolvimento agrícola e rural e, por outro, avaliar com precisão o efeito interativo da consolidação de terras e fatores relacionados, juntamente com os efeitos desse processo na evolução dos sistemas agronômicos.