http://yetl.yabesh.ir/yetl1/handle/yetl/18993 2026-04-07T13:10:38Z http://yetl.yabesh.ir/yetl1/handle/yetl/4310070 High-Precision Diameter Detector for Nuclear Power Main Water Supply System Pipelines Yaming Xu; Jian Yu; Cheng Xing; Jianguo Zhou; Pai Pan; Peng Yang In this paper, a high-precision technique for detecting the inner diameter of pipes in the two-loop main feedwater system of pressurized water reactor (PWR) nuclear power plants is proposed, which realizes the accurate detection of the inner diameter of the pipes. Based on the original measurement data, we establish a reference coordinate system and obtain the coordinates of measuring points on the inner wall of the pipe through coordinate transformation. Based on the original data, the reference coordinate system is established, and the coordinates of the measuring points on the inner wall of the pipe are obtained through coordinate transformation. These coordinates, combined with the shape of the inner wall of the pipe, are used to construct a three-dimensional model of the pipe to be measured, allowing us to determine its inner diameter. In addition, based on the proposed diameter detection technology, we have developed the ARE360 diameter detector for pipe measurement and calibrated the offset center of the ranging using the Whale Optimization Algorithm. Finally, the usability and accuracy of the detector are experimentally verified. The experimental results demonstrate that the developed pipeline internal diameter detection equipment can accurately measure the internal diameter of the pipeline of the two-loop main feedwater system of a PWR nuclear power plant. 2025-01-01T00:00:00Z http://yetl.yabesh.ir/yetl1/handle/yetl/4310069 Comparison between a Two-Wavelength Absolute Distance Meter and a GNSS-Based Distance Meter at CERN Geodetic Network Joffray Guillory; Sergio Baselga; Jean-Pierre Wallerand; Daniel Truong; Luis García-Asenjo; Raquel Luján; Damien Pesce; Benjamin Weyer; Jean-Frederic Fuchs; Dominique Missiaen Absolute distance determination, which is the determination of distances consistent with the International System of Units (SI) definition of meter, is a current challenge for distances of several kilometers in the open air and with submillimetric accuracies, which is being increasingly demanded for scientific and technological applications. We present the first comparison of two techniques recently developed for this purpose: the Arpent Absolute Distance Meter and the improved Global Navigation Satellite System (GNSS)-based distance meter. Both techniques have been tested and compared on the European Organization for Nuclear Research (CERN) geodetic network during a 2-week observation campaign. The results obtained include the rigorous determination of the uncertainties for both methodologies. In the end, four baselines of 2.2, 4.8, 6.0, and 6.5 km were measured, and for three of them, the differences between the two systems were less than 0.7 mm. The baseline of 4.8 km showed a difference of 2.7 mm, i.e., about 0.6 parts per million (ppm): in the case of conventional optical telemetry, such an agreement would require refractivity correction with knowledge of the air temperature and pressure at better than 0.6 K and 0.15 hPa, respectively. 2025-01-01T00:00:00Z http://yetl.yabesh.ir/yetl1/handle/yetl/4306827 Artificial Neural Network–Based Modeling and Prediction of GNSS Ionospheric Errors in Egypt A. Abdelmaaboud; T. Fathallah; A. Ragheb; A. Gomaa; T. Hassan One of the major error sources in Global Navigation Satellite Systems (GNSS) positioning is the signal propagation in the ionospheric layer. For low-accuracy real-time applications, the basic ionospheric models can be used to estimate the error budget of this effect. On the other hand, high-accuracy real-time applications necessitate the availability of a dual-frequency receiver to employ the ionosphere-free linear combination and eliminate most of the ionospheric effect. However, achieving a high positioning accuracy using a single-frequency receiver remains a challenge. This study explores the potential of using artificial neural networks (ANNs) for predicting the ionospheric errors influenced by the vertical total electron content (VTEC) across Egypt. The research utilizes data from 11 permanent GNSS stations covering Egypt over 10 years, in addition to information about the sunspot numbers, the planetary K-indices, and the electron densities at the F2 peak. Several ANNs are developed to identify the optimal number of hidden layers and number of neurons. The results indicate that an ANN with three hidden layers and 50 neurons can deliver the best performance. The prediction capability of the developed model is assessed using GNSS observations from an independent station. This shows promising VTEC predictions with a mean error value of 2.11TECU and a root mean square error (RMSE) value of 2.67TECU. Moreover, two field experiments (static and kinematic) are conducted to emphasize the significance of employing ANN ionospheric models in improving positional solutions. The epoch-wise accuracy improvement reaches 2.32 m (95.5%) and 6.86 m (46.8%) in the static and kinematic tests, respectively. 2025-01-01T00:00:00Z http://yetl.yabesh.ir/yetl1/handle/yetl/4306826 Evaluation of a Terrestrial Laser Scanner According to the ISO 17123-9 Standard María-Eugenia Polo; Alonso Sánchez-Ríos; Pedro J. Pardo Currently, the use of terrestrial laser scanners (TLSs) for point cloud recording is widespread in the fields of architecture, engineering, and construction (AEC), with dimensional tolerance requirements ranging from a few millimeters to several centimeters. The technical specifications of TLSs define the nominal three-dimensional (3D) point accuracy based on distance. In practice, both the design of the TLS and the proprietary software calculation algorithms are key factors in the competition between manufacturers and are therefore not public. This, together with the multiple determinants of each type of work, makes it difficult to assume those values; so, it becomes necessary to use external models to study TLS error sources and standardized evaluation test procedures to determine and evaluate the precision of a TLS and its measurement uncertainties. In this work, we use the international standard ISO 17123-9 to evaluate a Leica TLS RTC360 scanner. We consider observation distances from 10 to 50 m, and use targets with different sizes and reflectance values measured with a Micro-Hyperspec hyperspectral camera. The results show that the use of optimal materials increases the range of the instrument used to automatically detect targets. Additionally, the uncertainties range between 2.7 and 3.9 mm (distances between 10 and 40 m), reaching values of 7.7 mm when the distance is extended to 50 m. Finally, some recommendations for improving the field procedure of this standard are described, with a focus on the interests of surveyors and highlighting the importance of the type of target used. The terrestrial laser scanner has become one of the standard instruments used for surveyor data collection. Like any instrument, the scanner exhibits measurement uncertainties and limitations. A professional surveyor is always concerned about instrument condition imposing possible negative repercussions on their work. This study presents a way to check the condition of the TLS and its auxiliary equipment using the ISO 17123-9 standard, which is a standard made specifically for that purpose. The professional surveyor will certainly find references to this standard in the technical specifications provided by the survey instrument manufacturer. The surveyor should be aware of this family of standards, and, in the specific case of TLS, the importance of auxiliary equipment (e.g., positioning targets), both the material they are made of and their position in relation to the scanner and environmental conditions. 2025-01-01T00:00:00Z