LSTM-Based Forecasting Model for GRACE Accelerometer Data

The Gravity Recovery and Climate Experiment (GRACE) satellite mission, spanning from 2002 to 2017, has provided a valuable dataset for monitoring variations in Earth's gravity field, enabling diverse applications in geophysics and hydrology. The mission was followed by GRACE Follow-On in 2018, continuing data collection efforts. The monthly Earth gravity field, derived from the integration different instruments onboard satellites, has shown inconsistencies due to various factors, including gaps in observations for certain instruments since the beginning of the GRACE mission. With over two decades of GRACE and GRACE Follow-On data now available, this paper proposes an approach to fill the data gaps and forecast GRACE accelerometer data. Specifically, we focus on accelerometer data and employ Long Short-Term Memory (LSTM) networks to train a model capable of predicting accelerometer data for all three axes. In this study, we describe the methodology used to preprocess the accelerometer data, prepare it for LSTM training, and evaluate the model's performance. Through experimentation and validation, we assess the model's accuracy and its ability to predict accelerometer data for the three axes. Our results demonstrate the effectiveness of the LSTM forecasting model in filling gaps and forecasting GRACE accelerometer data

Tuning a gravimetric quasigeoid to GPS-levelling by non-stationary least-squares collocation

This paper addresses implementation issues in order to apply non-stationary least-squares collocation (LSC) to a practical geodetic problem: fitting a gravimetric quasigeoid to discrete geometric quasigeoid heights at a local scale. This yields a surface that is useful for direct GPS heighting. Non-stationary covariance functions and a nonstationary model of the mean were applied to residual gravimetric quasigeoid determination by planar LSC in the Perth region ofWestern Australia. The non-stationarymodel of the mean did not change the LSC results significantly. However, elliptical kernels in non-stationary covariance functions were used successfully to create an iterative optimisation loop to decrease the difference between the gravimetric quasigeoid and geometric quasigeoid at 99 GPS-levelling points to a user-prescribed tolerance

A review of non-stationary spatial methods for geodetic least-squares collocation

This paper reviews a field that is herein termed spatial ?non-stationarity?, which is specifically concerned with non-stationarity in the geodetic theory of least-squares collocation (LSC). In practice, many geodesists rely on stationary assumptions in LSC, i.e., using a constant mean and isotropic and spatially invariant covariance for estimation and prediction of geodetic quantities. However, new theories in spatial statistics and geostatistics allow for better statistical methodologies to be used in geodesy. The aim of this paper is to introduce these methodologies and adapt them for dealing with non-stationarity in LSC

Particle Motion in Flows: Contributions to Airborne Aerosol Measurement

Accurate, in situ measurement of airborne particles is critical in understanding the global atmosphere. An airborne instrument is designed to sample and measure the aerodynamic diameter of particles in the size range of 1-30 mm. Knowledge of the aerodynamic size of a particle includes the impact of unknown variables such as shape, size and density of a particle. Particles of the same aerodynamic diameter have the same trajectory and settling velocity in air, regardless of their actual size, density or shape. Knowing the time a particle resides in air can improve the climate models substantially. The developed instrument consists of a low turbulence inlet and a laser-Doppler velocimeter to sample and measure the super-micron particles all in one unit. Air enters the inlet at true air speed of the aircraft, which is a relatively high speed in the range of 100-200 ms-1. The low turbulence inlet reduces the air speed to 5-10 ms-1 in a short distance without generation of additional turbulence. It uses boundary layer suction through a porous diffuser to remove a substantial amount of air that is responsible for turbulence generation and particle loss in deposition to the inlet walls. Reduction of turbulence makes it possible to model and solve the flows inside the inlets and calculate the particle trajectories using computational fluid dynamic (CFD) tools. A new technique is developed to determine the size distribution of particles based on the motion of particles and measurement of the particles\u27 velocity. Velocimetric measurement of particle size is achieved by slowing the velocity of the flow that is carrying the particles and measuring the velocity of the particles in response to this change. Larger particles have higher tendency to continue at a higher speed, while smaller particles tend to follow the air stream lines. A laser Doppler velocimeter (LDV) measures the velocity of the particles as they pass through the viewing volume of the velocimeter. The aerodynamic diameter of the particles and their concentration is determined from the velocity measurements. Accurate determination of particle size distribution at the location of measuring sensor does not guarantee the accuracy of the ambient size distribution. The modification of number of particle due to particle loss, enhancement, and particles bouncing off the leading edge of the inlet is considered to accurately measure the ambient size distribution of particles. This research work also focuses on quantifying the effects of particle enhancement in the low turbulence inlet used in ACE-Asia sampling inlet and the deposition of particles in transport through the bends of ACE-Asia and NOAA inlets. The effect of force of gravity on deposition efficiency of particles has also been analyzed

Progress Towards the New Australian Geoid-type Model as a Replacement for AUSGeoid98

We are nearing the final stages of producing a new geoid-type model for Australia that will replace AUSGeoid98. The terminology geoid-type reflects that the gravimetric quasigeoid model will be fitted to Australia-wide GPS-levelling data, probably using least-squares collocation. This will provide a user-friendly product for the more direct transformation of GPS-derived ellipsoidal heights to normal-orthometric heights on the Australian Height Datum (AHD). This has become necessary because Australian government geodetic authorities have decided to retain the AHD for the 'foreseeable future', whereas it is well known that the AHD contains about 1-2m distortions mainly due to fixing the AHD height to zero at 32 tide gauges. Another driver is that there is an increasing trend towards establishing vertical control using carrier-phase GPS via the single-point precise point positioning (PPP) technique or over very long baselines using the AUSPOS on-line service. When the quasigeoid model was used with differential GPS over short baselines, common/correlated errors cancelled in this relative mode, whereas they do not in the absolute or long-baseline modes. As such, AUSPOS and PPP users of AUSGeoid98 can sometimes find up to 2m discrepancies with existing AHD benchmarks. In addition, we will use improved quasigeoid modelling techniques and the most recent datasets available, such as GRACE (Gravity Recovery and Climate Experiment) global gravity field models, satellite-altimeter-derived gravity anomalies in marine areas that have been re-tracked to improve them in the coastal zone, the latest cleaned release of the Australian land gravity database, the version 2 Australian digital elevation model, which now allows the computation of nine arc-second resolution topographical effects. Some emphasis will be placed on the use of modified kernels as high-pass filters to manage long-wavelength errors in the Australian terrestrial gravity and terrain data, so that they do not contaminate the high-quality GRACE data

Survival of COVID-19 patients requires precise immune regulation: The hypothetical immunoprotective role of nicotinic agonists

Summary recent studies have provided novel evidence regarding the effect of nicotine agonists on the prevention or modulation of cytokines storm and reduction of infection. In this study we tried to attempt to address these issues from a therapeutic perspective of nicotine agonists in this manner and we describe one of the most challenging theories of immunotherapy in coronavirus-19 (COVID-19). The analysis of the proposed mechanism goes beyond the physiological consequences of a way to design new strategies to provide anti-inflammatory drugs. © 2020 Elsevier Lt

Investigating the expressions of miRNA-125b and TP53 in endometriosis. Does it underlie cancer-like features of endometriosis? A case-control study

Background: Endometriosis is generally considered as a benign condition; however, there is a possibility for it to become cancerous. miR-125b is upregulated in both endometriotic tissues and serum samples of women with endometriosis but its potential targets in endometriosis are still not fully understood. Objective: The role of miR-125b in the regulation of TP53 expression in endometriosis was tested with a bioinformatics approach. In addition, the expression of miR-125b and TP53 in both eutopic (Eu-p) and ectopic endometrium (Ec-p) in the endometrium tissues of women with endometriosis was compared to those in the normal endometrium tissues of controls (Normal). Materials and Methods: In this case-control study, the Eu-p and Ec-p samples were collected from 20 women who underwent laparoscopic surgery, and the normal endometrium tissues were collected from 20 controls with no evidence of endometriosis. For bioinformatics approach, a protein-protein interaction network was constructed based on co-expressed potential targets of miR-125b. Quantitative polymerase chain reaction technique was used for the measurement of miR125b and TP53 expression. Results: Our results showed that miR-125b was significantly overexpressed in Ec-p (p-value: 0.021). In addition, there was a significant TP53 under expression in both the Ec-p and Eu-p samples compared with the Normal tissues (p-value: 0.003). Conclusion: The negative correlation between miR-125b and TP53 as well as a noticeable decreased expression of TP53 in both Ec-p and Eu-p samples may be interpreted as the roles of miR-125b/TP53 axis in the pathogenesis of endometriosis. In addition, these findings and bioinformatic analyses imply a possible role of miR-125b in cancer-like features of endometriosis. Key words: Endometriosis, TP53, miR-125b, Ectopic endometrium, Eutopic endometrium

How Students View the Role of Faculty Advisors in the SWE Organization

The Society of Women Engineers (SWE) collegiate sections attract many men and women to the society, and they can be among the largest and most active student organizations on the university campuses. A key factor to boost membership is the active involvement of faculty advisors, who serve as the liaison between SWE collegiate sections, the university, the National SWE organization, and professional SWE members. A group of SWE faculty advisors previously conducted a survey of faculty advisors and counselors, with advisors and counselors aggregated in the results, to determine what aspects of their role they consider most significant, and how they engage with the students. The study showed that faculty advisors play an important role in providing continuity to the section, participation in and understanding of the larger organization, and in mentoring students on both general leadership and SWE leadership. This paper examines how students view the role of their faculty advisor in their SWE collegiate section. The objectives of this study are to understand the challenges that collegiate sections face and what types of support they need from their faculty advisor. A survey about the level of importance of different roles of faculty advisors was conducted. Additional ways students feel their faculty advisor could help them was also addressed. The data was analyzed to identify key factors that faculty advisors should consider while serving in these roles within student sections. The findings were then compared to the results of the self-assessment of the faculty advisors

Instrument data simulations for GRACE Follow-on: Observation and noise models

The Gravity Recovery and Climate Experiment (GRACE) mission has yielded data on the Earth's gravity field to monitor temporal changes for more than 15 years. The GRACE twin satellites use microwave ranging with micrometre precision to measure the distance variations between two satellites caused by the Earth's global gravitational field. GRACE Follow-on (GRACE-FO) will be the first satellite mission to use inter-satellite laser interferometry in space. The laser ranging instrument (LRI) will provide two additional measurements compared to the GRACE mission: Interferometric inter-satellite ranging with nanometre precision and inter-satellite pointing information. We have designed a set of simulated GRACE-FO data, which include LRI measurements, apart from all other GRACE instrument data needed for the Earth's gravity field recovery. The simulated data files are publicly available via https://doi.org/10.22027/AMDC2 and can be used to derive gravity field solutions like from GRACE data. This paper describes the scientific basis and technical approaches used to simulate the GRACE-FO instrument data.data. This paper describes the scientific basis and technical approaches used to simulate the GRACE-FO instrument data

Development of Soil Compaction Analysis Software (SCAN) Integrating a Low Cost GPS Receiver and Compactometer

A software for soil compaction analysis (SCAN) has been developed for evaluating the compaction states using the data from the GPS as well as a compactometer attached on the roller. The SCAN is distinguished from other previous software for intelligent compaction (IC) in that it can use the results from various types of GPS positioning methods, and it also has an optimal structure for remotely managing the large amounts of data gathered from numerous rollers. For this, several methods were developed: (1) improving the accuracy of low cost GPS receiver’s positioning results; (2) modeling the trajectory of a moving roller using a GPS receiver’s results and linking it with the data from the compactometer; and (3) extracting the information regarding the compaction states of the ground from the modeled trajectory, using spatial analysis methods. The SCAN was verified throughout various field compaction tests, and it has been confirmed that it can be a very effective tool in evaluating field compaction states