Displacement monitoring using multi-technique antenna calibrations in processing GNSS data from multi-frequency low-cost receivers

2021 ◽  
Author(s):  
Andrea Gatti ◽  
Giulio Tagliaferro ◽  
Eugenio Realini
Keyword(s):  
Environmental Changes ◽  
Low Cost ◽  
Integrated Monitoring ◽  
Advanced Technique ◽  
Phase Measurements ◽  
System A ◽  
Phase Center Variation ◽  
The Stability ◽  
Processing Techniques ◽  
Gnss Data

<p>In the framework of the EU founded GIMS-Project (Geodetic Integrated Monitoring System), a low-cost solution for detecting and measuring ground movements have been developed (https://www.gims-project.eu/). In particular, our focus was the improvement of processing techniques of multi-constellation GNSS data from low-cost devices, culminated in the development of improved algorithms implemented now in the goGPS open-source software (https://gogps-project.github.io). The goGPS engine has been used to analyse the motion of two different landslides in Slovenia. It is currently successfully employed to monitor, in near real-time, numerous landslides and structures.</p><p>During the last year, we developed an advanced technique to improve the on-site calibration of the low-cost antennas that allows a drastic improvement of the stability of sub-daily coordinates. This approach is based on iterative steps designed to filter the multipath affecting phase measurements and the phase center variation of the antennas.</p><p>A first solution using more than 10 days of data is computed with the goal of retrieving phase residuals. Then these residuals are filtered using a combination of Zernike polynomials interpolation and multi-resolution gridding in order to obtain hemi-spherical maps able to correct the observations of longer periods. A final solution is finally obtained applying the stored corrections.</p><p>Eventually the procedure can be iterated to reach convergence and maps can be updated after environmental changes.</p><p>By using these maps in a multi-constellation environment, the monitoring of displacements is feasible with low-cost receivers (single and multi-frequencies) even in challenging conditions. The accuracy improvements are higher than 50% with respect to a scenario without maps.</p><p>In this work, the processing procedure of low-cost receivers is presented with examples of successful monitoring experiences<strong>.</strong></p>

scholarly journals Modeling and Optimal Design for a High Stability 2D Optoelectronic Angle Sensor

Sensors ◽  
2019 ◽  
Vol 19 (20) ◽  
pp. 4409 ◽  
Author(s):  
Cheng ◽  
Liu ◽  
Xu ◽  
Li ◽  
Fan ◽  
...  
Keyword(s):  
Optimal Design ◽  
Environmental Changes ◽  
Design Method ◽  
Low Cost ◽  
High Precision Measurement ◽  
Element Analysis ◽  
Angle Sensor ◽  
Structural Deformations ◽  
Optimal Design Method ◽  
The Stability

The structural deformations caused by environmental changes in temperature, vibration, and other factors are harmful to the stability of high precision measurement equipment. The stability and optimal design method of a 2D optoelectronic angle sensor have been investigated in this study. The drift caused by structural deformations of the angle sensor has been studied and a drift error model has been achieved. Key components sensitive to thermal and vibrational effects were identified by error sensitivity analysis and simulation. The mounts of key components were analyzed using finite element analysis software and optimized based on the concept of symmetric structures. Stability experiments for the original and optimized angle sensors have been carried out for contrast. As a result, the stability of the optimized angle sensor has been improved by more than 63%. It is verified that the modeling and optimal design method is effective and low-cost, which can also be applied to improve the stability of other sensors with much more complex principles and structures.

scholarly journals Promoting synthetic symbiosis under environmental disturbances

2018 ◽  
Author(s):  
Jai A. Denton ◽  
Chaitanya S. Gokhale
Keyword(s):  
Theoretical Model ◽  
Simple Model ◽  
Ecological Niche ◽  
Environmental Changes ◽  
Cooperative Interaction ◽  
Environmental Disturbances ◽  
Complex Interactions ◽  
System A ◽  
The Stability ◽  
The Cost

By virtue of complex interactions, the behaviour of mutualistic systems is difficult to study and nearly impossible to predict. We have developed a theoretical model of a modifiable experimental yeast system that is amenable to exploring self-organised cooperation while considering the production and use of specific metabolites. Leveraging the simplicity of an artificial yeast system, a simple model of mutualism, we develop and test the assumptions and stability of this theoretical model. We examine how one-off, recurring and permanent changes to an ecological niche affect a cooperative interaction and identify an ecological “Goldilocks zone” in which the mutualism can survive. Moreover, we explore how a factor like the cost of mutualism – the cellular burden of cooperating – influences the stability of mutualism and how environmental changes shape this stability. Our results highlight the fragility of mutualisms and suggest the use of synthetic biology to stave off an ecological collapse.

NPLs — The Solution Recipe for Albania

2015 ◽  
Vol 3 (1) ◽  
pp. 48
Author(s):  
Elona Shehu ◽  
Elona Meka
Keyword(s):  
Interest Rate ◽  
Negative Relationship ◽  
Banking System ◽  
Gdp Growth ◽  
System A ◽  
Analysis Technique ◽  
Recent Financial Crisis ◽  
The Stability ◽  
Asset Quality ◽  
Macroeconomic Determinants

The quality of the loan portfolio in Albanian banking system is facing many obstacles during the last decade. In this paper we look at possible determinants of assets quality. During the recent financial crisis commercial banks were confronted with deteriorating asset quality that threatened not only the banking industry, but also the stability of the entire financial system. This study aims to examine the correlation between non-performing loans and the macroeconomic determinants in Albania during the last decade. NPLs are considered to be of a high importance as they represent the high risk exposure of banking system. A solid bank with healthy assets increases the market efficiency. Our approach is based on a panel data regression analysis technique from 2005-2015. Within this methodology this study finds robust evidence on the existing relationship between lending interest rate, real GDP growth and NPLs. We expect to find a negative relationship between lending interest rate and asset quality. Further we assume an inverse relationship between GDP growth and non-performing loans, suggesting that NPLs decrease if the economy is growing. Furthermore this study proposes a solution platform, which looks deeper into the possibility of creating a secondary active market for troubled loans, restructuring the banking system or implementing the Podgorica model. This research paper opens a new lieu of discussion in terms of academic debates and decision-making policies.

Towards a new design with generic modeling and adaptive control of a transformable quadrotor

2021 ◽  
pp. 1-31
Author(s):  
S.H. Derrouaoui ◽  
Y. Bouzid ◽  
M. Guiatni
Keyword(s):  
Adaptive Control ◽  
Control Strategy ◽  
Experimental Tests ◽  
Generic Model ◽  
System Control ◽  
System A ◽  
Viable Solution ◽  
Generic Modeling ◽  
Adaptive Control Strategy ◽  
The Stability

Abstract Recently, transformable Unmanned Aerial Vehicles (UAVs) have become a subject of great interest in the field of flying systems, due to their maneuverability, agility and morphological capacities. They can be used for specific missions and in more congested spaces. Moreover, this novel class of UAVs is considered as a viable solution for providing flying robots with specific and versatile functionalities. In this paper, we propose (i) a new design of a transformable quadrotor with (ii) generic modeling and (iii) adaptive control strategy. The proposed UAV is able to change its flight configuration by rotating its four arms independently around a central body, thanks to its adaptive geometry. To simplify and lighten the prototype, a simple mechanism with a light mechanical structure is proposed. Since the Center of Gravity (CoG) of the UAV moves according to the desired morphology of the system, a variation of the inertia and the allocation matrix occurs instantly. These dynamics parameters play an important role in the system control and its stability, representing a key difference compared with the classic quadrotor. Thus, a new generic model is developed, taking into account all these variations together with aerodynamic effects. To validate this model and ensure the stability of the designed UAV, an adaptive backstepping control strategy based on the change in the flight configuration is applied. MATLAB simulations are provided to evaluate and illustrate the performance and efficiency of the proposed controller. Finally, some experimental tests are presented.

scholarly journals Post-Processing Techniques for the Improvement of Liposome Stability

Pharmaceutics ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1023
Author(s):  
Ji Young Yu ◽  
Piyanan Chuesiang ◽  
Gye Hwa Shin ◽  
Hyun Jin Park
Keyword(s):  
Freeze Drying ◽  
Protective Agent ◽  
Post Processing ◽  
Additional Process ◽  
Spray Freeze Drying ◽  
The Stability ◽  
Processing Techniques ◽  
The Impact ◽  
Self Aggregation ◽  
Liposome Stability

Liposomes have been utilized as a drug delivery system to increase the bioavailability of drugs and to control the rate of drug release at the target site of action. However, the occurrence of self-aggregation, coalescence, flocculation and the precipitation of aqueous liposomes during formulation or storage can cause degradation of the vesicle structure, leading to the decomposition of liposomes. To increase the stability of liposomes, post-processing techniques have been applied as an additional process to liposomes after formulation to remove water and generate dry liposome particles with a higher stability and greater accessibility for drug administration in comparison with aqueous liposomes. This review covers the effect of these techniques including freeze drying, spray drying and spray freeze drying on the stability, physicochemical properties and drug encapsulation efficiency of dry liposomes. The parameters affecting the properties of liposomes during the drying process are also highlighted in this review. In addition, the impact of using a protective agent to overcome such limitations of each process is thoroughly discussed through various studies.

scholarly journals Multi-Blockchain-Based IoT Data Processing Techniques to Ensure the Integrity of IoT Data in AIoT Edge Computing Environments

Sensors ◽  
2021 ◽  
Vol 21 (10) ◽  
pp. 3515
Author(s):  
Sung-Ho Sim ◽  
Yoon-Su Jeong
Keyword(s):  
Low Cost ◽  
Third Party ◽  
Monitoring And Control ◽  
Constant Size ◽  
Computing Environments ◽  
Iot Devices ◽  
Cloud Servers ◽  
The Cost ◽  
Processing Techniques ◽  
And Control

As the development of IoT technologies has progressed rapidly recently, most IoT data are focused on monitoring and control to process IoT data, but the cost of collecting and linking various IoT data increases, requiring the ability to proactively integrate and analyze collected IoT data so that cloud servers (data centers) can process smartly. In this paper, we propose a blockchain-based IoT big data integrity verification technique to ensure the safety of the Third Party Auditor (TPA), which has a role in auditing the integrity of AIoT data. The proposed technique aims to minimize IoT information loss by multiple blockchain groupings of information and signature keys from IoT devices. The proposed technique allows IoT information to be effectively guaranteed the integrity of AIoT data by linking hash values designated as arbitrary, constant-size blocks with previous blocks in hierarchical chains. The proposed technique performs synchronization using location information between the central server and IoT devices to manage the cost of the integrity of IoT information at low cost. In order to easily control a large number of locations of IoT devices, we perform cross-distributed and blockchain linkage processing under constant rules to improve the load and throughput generated by IoT devices.

scholarly journals Exploring the Structural Competition between the Black and the Yellow Phase of CsPbI3

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1282
Author(s):  
Ioannis Deretzis ◽  
Corrado Bongiorno ◽  
Giovanni Mannino ◽  
Emanuele Smecca ◽  
Salvatore Sanzaro ◽  
...  
Keyword(s):  
Perovskite Phase ◽  
Low Cost ◽  
Δ Phase ◽  
Nanocrystalline Structures ◽  
Halide Perovskites ◽  
The Stability ◽  
Structural Competition ◽  
Lead Halide ◽  
Main Candidate ◽  
Spontaneous Phase

The realization of stable inorganic perovskites is crucial to enable low-cost solution-processed photovoltaics. However, the main candidate material, CsPbI3, suffers from a spontaneous phase transition at room temperature towards a photo-inactive orthorhombic δ-phase (yellow phase). Here we used theoretical and experimental methods to study the structural and electronic features that determine the stability of the CsPbI3 perovskite. We argued that the two physical characteristics that favor the black perovskite phase at low temperatures are the strong spatial confinement in nanocrystalline structures and the level of electron doping in the material. Within this context, we discussed practical procedures for the realization of long-lasting inorganic lead halide perovskites.

scholarly journals Longevity of Raw and Lyophilized Crude Urease Extracts

2021 ◽  
Vol 2 (2) ◽  
pp. 325-334
Author(s):  
Neda Javadi ◽  
Hamed Khodadadi Tirkolaei ◽  
Nasser Hamdan ◽  
Edward Kavazanjian
Keyword(s):  
Crude Extract ◽  
Room Temperature ◽  
Low Cost ◽  
Extraction Process ◽  
Crude Extracts ◽  
Simple Extraction ◽  
Commercial Applications ◽  
Stable Source ◽  
The Stability ◽  
The Cost

The stability (longevity of activity) of three crude urease extracts was evaluated in a laboratory study as part of an effort to reduce the cost of urease for applications that do not require high purity enzyme. A low-cost, stable source of urease will greatly facilitate engineering applications of urease such as biocementation of soil. Inexpensive crude extracts of urease have been shown to be effective at hydrolyzing urea for carbonate precipitation. However, some studies have suggested that the activity of a crude extract may decrease with time, limiting the potential for its mass production for commercial applications. The stability of crude urease extracts shown to be effective for biocementation was studied. The crude extracts were obtained from jack beans via a simple extraction process, stored at room temperature and at 4 ℃, and periodically tested to evaluate their stability. To facilitate storage and transportation of the extracted enzyme, the longevity of the enzyme following freeze drying (lyophilization) to reduce the crude extract to a powder and subsequent re-hydration into an aqueous solution was evaluated. In an attempt to improve the shelf life of the lyophilized extract, dextran and sucrose were added during lyophilization. The stability of purified commercial urease following rehydration was also investigated. Results of the laboratory tests showed that the lyophilized crude extract maintained its activity during storage more effectively than either the crude extract solution or the rehydrated commercial urease. While incorporating 2% dextran (w/v) prior to lyophilization of the crude extract increased the overall enzymatic activity, it did not enhance the stability of the urease during storage.

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