IoT Data Validation Using Spatial and Temporal Correlations

AbstractThe investigations on low-cost single frequency GNSS receivers at the Institute of Engineering Geodesy (IIGS) show that u-blox GNSS receivers combined with low-cost antennas and self-constructed L1-optimized choke rings can reach an accuracy which almost meets the requirements of geodetic applications (see Zhang and Schwieger [25]). However, the quality (accuracy and reliability) of low-cost GNSS receiver data should still be improved, particularly in environments with obstructions. The multipath effects are a major error source for the short baselines. The ground plate or the choke ring ground plane can reduce the multipath signals from the horizontal reflector (e. g. ground). However, the shieldings cannot reduce the multipath signals from the vertical reflectors (e. g. walls).Because multipath effects are spatially and temporally correlated, an algorithm is developed for reducing the multipath effect by considering the spatial correlations of the adjoined stations (see Zhang and Schwieger [24]). In this paper, an algorithm based on the temporal correlations will be introduced. The developed algorithm is based on the periodic behavior of the estimated coordinates and not on carrier phase raw data, which is easy to use. Because, for the users, coordinates are more accessible than the raw data. The multipath effect can cause periodic oscillations but the periods change over time. Besides this, the multipath effect’s influence on the coordinates is a mixture of different multipath signals from different satellites and different reflectors. These two properties will be used to reduce the multipath effect. The algorithm runs in two steps and iteratively. Test measurements were carried out in a multipath intensive environment; the accuracies of the measurements are improved by about 50 % and the results can be delivered in near-real-time (in ca. 30 minutes), therefore the algorithm is suitable for structural health monitoring applications.

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Estimation of PWC gradients over the Kanto Plain using GPS data: Validation and possible meteorological implications

Earth Planets and Space ◽

10.1186/bf03352304 ◽

2000 ◽

Vol 52 (11) ◽

pp. 907-912 ◽

Cited By ~ 7

Author(s):

Kazumasa Aonashi ◽

Yoshinori Shoji ◽

Ryu-ichi Ichikawa ◽

Hiroshi Hanado

Keyword(s):

Gps Data ◽

Data Validation

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VEGF as a potential molecular target in periodontitis: a meta-analysis and microarray data validation

Journal of Inflammation ◽

10.1186/s12950-021-00281-9 ◽

2021 ◽

Vol 18 (1) ◽

Author(s):

Bo Ren ◽

Que Feng ◽

Shan He ◽

Yanfeng Li ◽

Jiadong Fan ◽

...

Keyword(s):

Growth Factor ◽

Clinical Sample ◽

Meta Analysis ◽

Enrichment Analysis ◽

Therapeutic Drug ◽

Data Validation ◽

Control Groups ◽

Vegf Expression ◽

Healthy Control

Abstract Background Anti-vascular endothelial growth factor (VEGF) has been used as a therapeutic drug for the treatment of some human diseases. However, no systematic evidence is performed for assessing the role of VEGF in periodontitis. We carried out a comprehensive analysis to explore the role of VEGF in patients with periodontitis. Methods Multiple databases were searched for eligible studies. The pooled standardized mean difference (SMD) and odds ratio (OR) with the corresponding 95% confidence interval (CI) were applied to evaluate the effect sizes. Clinical data validation from microarray analysis was used. Pathway and process enrichment analysis were also investigated. Results Finally, 16 studies were included in this analysis. Overall, there was a significantly higher level of VEGF expression in periodontitis than in healthy control groups (OR = 16.64, 95% CI = 6.01–46.06, P < 0.001; SMD = 2.25, 95% CI = 1.25–3.24, P < 0.001). Subgroup analysis of ethnicity showed that VEGF expression was still correlated with periodontitis in the Asian and European populations. No correlation was observed between VEGF expression and age, gender, and pathological type. A large clinical sample data (427 periodontitis patients and 136 healthy controls) further validated that VEGF expression was higher in periodontitis than in healthy control groups (P = 0.023). VEGF was involved in many functions such as blood vessel development, response to growth factor, cell proliferation, and cell adhesion. Conclusions High levels of VEGF were credible implications for the development of periodontitis. Anti-VEGF therapy may be valuable for the treatment of periodontitis in clinical management.

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Formative and Summative Validation of Building Information Model-Based Cadastral Data

Land ◽

10.3390/land10080822 ◽

2021 ◽

Vol 10 (8) ◽

pp. 822

Author(s):

Ali Asghari ◽

Mohsen Kalantari ◽

Abbas Rajabifard

Keyword(s):

Integrated Management ◽

Summative Assessment ◽

3D Models ◽

Legal Aspects ◽

Data Validation ◽

Data Generation ◽

Study Approach ◽

Spatial Consistency ◽

Information Models ◽

Building Information

Among 3D models, Building Information Models (BIM) can potentially support the integrated management of buildings’ physical and legal aspects in cadastres. However, there is not a systematic approach to author the cadastral information into the BIM models. Moreover, the common approaches for data validation only check the final cadastral output, and they ignore the data generation steps as potential avenues for validation. Therefore, this study aims to develop the criteria and standards to check the spatial consistency and integrity of BIM-based cadastral data in the process of generating the data. The paper utilises a case study approach as its methodology to investigate the requirements of generating a BIM-based cadastral model and identify the issues within the process. The results include a formative assessment (i.e., multistep validation approach during the data generation) alongside a summative assessment (i.e., one-step validation approach at the end of data generation). This study found the summative assessment alone insufficient for 3D cadastral data validation. The paper concludes that a formative and summative assessment together can improve the validity of the data. The results will potentially bring more efficiency to modern land administration processes by avoiding the accumulation of errors in 3D cadastral data generation.

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