TanDEM-X DEM: Comparative performance review employing LIDAR data and DSMs

2020 ◽

Vol 7 (2) ◽

Author(s):

Nelci Dessy Rumlaklak

Keyword(s):

Path Planning ◽

Optimality Criteria ◽

Computational Time ◽

Comparative Performance ◽

Performance Review ◽

Probabilistic Roadmap ◽

Simulation Based ◽

Planning Algorithms ◽

Working Parameters ◽

Conclusion Section

This paper will discuss a comparative performance review of several path planning algorithms. This study compares five well-known path planning algorithms, namely the Probabilistic Roadmap (PRM), Rapidly-exploring Random Tree (RRT), RRT* and Informed-RRT* algorithm. Testing is done through simulation based experiments using python. The test was conducted using several existing benchmark cases, namely narrow, maze, trap and clutter environment. The optimality criteria compared are path costs, computational time and the total number of nodes in the tree needed. The results of this study will provide information to readers about which algorithm is most suitable for use in user applications where there are several working parameters to be optimized. The findings have been summarized in the conclusion section. Keywords : Motion planning, PRM, RRT, RRT*, Informed-RRT*

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Processing Strategy and Comparative Performance of Different Mobile LiDAR System Grades for Bridge Monitoring: A Case Study

Sensors ◽

10.3390/s21227550 ◽

2021 ◽

Vol 21 (22) ◽

pp. 7550

Author(s):

Yi-Chun Lin ◽

Jidong Liu ◽

Yi-Ting Cheng ◽

Seyyed Meghdad Hasheminasab ◽

Timothy Wells ◽

...

Keyword(s):

Laser Scanning ◽

Three Dimensional ◽

Lidar Data ◽

Large Area ◽

Comparative Performance ◽

High Resolution Data ◽

Bridge Monitoring ◽

System Calibration ◽

Wide Range ◽

The Impact

Collecting precise as-built data is essential for tracking construction progress. Three-dimensional models generated from such data capture the as-is conditions of the structures, providing valuable information for monitoring existing infrastructure over time. As-built data can be acquired using a wide range of remote sensing technologies, among which mobile LiDAR is gaining increasing attention due to its ability to collect high-resolution data over a relatively large area in a short time. The quality of mobile LiDAR data depends not only on the grade of onboard LiDAR scanners but also on the accuracy of direct georeferencing information and system calibration. Consequently, millimeter-level accuracy is difficult to achieve. In this study, the performance of mapping-grade and surveying-grade mobile LiDAR systems for bridge monitoring is evaluated against static laser scanners. Field surveys were conducted over a concrete bridge where grinding was required to achieve desired smoothness. A semi-automated, feature-based fine registration strategy is proposed to compensate for the impact of georeferencing and system calibration errors on mobile LiDAR data. Bridge deck thickness is evaluated using surface segments to minimize the impact of inherent noise in the point cloud. The results show that the two grades of mobile LiDAR delivered thickness estimates that are in agreement with those derived from static laser scanning in the 1 cm range. The mobile LiDAR data acquisition took roughly five minutes without having a significant impact on traffic, while the static laser scanning required more than three hours.

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Success Strategies: Implementing the Professional Performance Review Process for School-Based Speech-Language Pathologists

Perspectives on Administration and Supervision ◽

10.1044/aas19.1.4 ◽

2009 ◽

Vol 19 (1) ◽

pp. 4-9

Author(s):

Jill Parmenter ◽

Sheryl Amaral ◽

Julia Jackson

Keyword(s):

Review Process ◽

Successful Implementation ◽

Speech Language Pathologists ◽

Self Advocacy ◽

Professional Performance ◽

Performance Review ◽

Roles And Responsibilities ◽

Speech Language Pathologist ◽

School Based ◽

Review Management

Abstract The Professional Performance Review Process for School-Based Speech-Language Pathologists (PPRP) (ASHA, 2006) was developed in response to the need for a performance review tool that fits school district requirements for performance review management while addressing the specific roles and responsibilities of a school-based speech-language pathologist (ASHA, 2006). This article will examine the purpose and components of the PPRP. A description of its use as a tool for self-advocacy will be discussed. Strategies for successful implementation of the PPRP will be explained using insight from speech-language pathologists and other professionals familiar with the PPRP.

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