Multi-level monitoring of three-dimensional building changes for megacities: Trajectory, morphology, and landscape

Remarkable progress in the development of modeling methods for indoor spaces has been made in recent years with a focus on the reconstruction of complex environments, such as multi-room and multi-level buildings. Existing methods represent indoor structure models as a combination of several sub-spaces, which are constructed by room segmentation or horizontal slicing approach that divide the multi-room or multi-level building environments into several segments. In this study, we propose an automatic reconstruction method of multi-level indoor spaces with unique models, including inter-room and inter-floor connections from point cloud and trajectory. We construct structural points from registered point cloud and extract piece-wise planar segments from the structural points. Then, a three-dimensional space decomposition is conducted and water-tight meshes are generated with energy minimization using graph cut algorithm. The data term of the energy function is expressed as a difference in visibility between each decomposed space and trajectory. The proposed method allows modeling of indoor spaces in complex environments, such as multi-room, room-less, and multi-level buildings. The performance of the proposed approach is evaluated for seven indoor space datasets.

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A Collision Dynamics Model of a Multi-Level Train

Rail Transportation ◽

10.1115/imece2006-13537 ◽

2006 ◽

Cited By ~ 5

Author(s):

Michelle Priante ◽

David Tyrell ◽

Benjamin Perlman

Keyword(s):

Three Dimensional ◽

Design Parameters ◽

Collision Dynamics ◽

Dynamics Model ◽

Single Level ◽

High Speeds ◽

Front End ◽

Multi Level ◽

Low Speeds ◽

Vertical Accelerations

In train collisions, multi-level rail passenger vehicles can deform in modes that are different from the behavior of single level cars. The deformation in single level cars usually occurs at the front end during a collision. In one particular incident, a cab car buckled laterally near the back end of the car. The buckling of the car caused both lateral and vertical accelerations, which led to unanticipated injuries to the occupants. A three-dimensional collision dynamics model of a multi-level passenger train has been developed to study the influence of multi-level design parameters and possible train configuration variations on the reactions of a multi-level car in a collision. This model can run multiple scenarios of a train collision. This paper investigates two hypotheses that could account for the unexpected mode of deformation. The first hypothesis emphasizes the non-symmetric resistance of a multi-level car to longitudinal loads. The structure is irregular since the stairwells, supports for tanks, and draglinks vary from side to side and end to end. Since one side is less strong, that side can crush more during a collision. The second hypothesis uses characteristics that are nearly symmetric on each side. Initial imperfections in train geometry induce eccentric loads on the vehicles. For both hypotheses, the deformation modes depend on the closing speed of the collision. When the characteristics are non-symmetric, and the load is applied in-line, two modes of deformation are seen. At low speeds, the couplers crush, and the cars saw-tooth buckle. At high speeds, the front end of the cab car crushes, and the cars remain in-line. If an offset load is applied, the back stairwell of the first coach car crushes unevenly, and the cars saw-tooth buckle. For the second hypothesis, the characteristics are symmetric. At low speeds, the couplers crush, and the cars remain in-line. At higher speeds, the front end crushes, and the cars remain in-line. If an offset load is applied to a car with symmetric characteristics, the cars will saw-tooth buckle.

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UAV Path Planning Based on Multi-Stage Constraint Optimization

Drones ◽

10.3390/drones5040144 ◽

2021 ◽

Vol 5 (4) ◽

pp. 144

Author(s):

Yong Shen ◽

Yunlou Zhu ◽

Hongwei Kang ◽

Xingping Sun ◽

Qingyi Chen ◽

...

Keyword(s):

Path Planning ◽

Three Dimensional ◽

Evolutionary Process ◽

Constraint Processing ◽

Multi Stage ◽

Planning Ability ◽

Path Constraints ◽

Aerial Vehicle ◽

Multi Level ◽

Processing Mechanism

Evolutionary Algorithms (EAs) based Unmanned Aerial Vehicle (UAV) path planners have been extensively studied for their effectiveness and high concurrency. However, when there are many obstacles, the path can easily violate constraints during the evolutionary process. Even if a single waypoint causes a few constraint violations, the algorithm will discard these solutions. In this paper, path planning is constructed as a multi-objective optimization problem with constraints in a three-dimensional terrain scenario. To solve this problem in an effective way, this paper proposes an evolutionary algorithm based on multi-level constraint processing (ANSGA-III-PPS) to plan the shortest collision-free flight path of a gliding UAV. The proposed algorithm uses an adaptive constraint processing mechanism to improve different path constraints in a three-dimensional environment and uses an improved adaptive non-dominated sorting genetic algorithm (third edition—ANSGA-III) to enhance the algorithm’s path planning ability in a complex environment. The experimental results show that compared with the other four algorithms, ANSGA-III-PPS achieves the best solution performance. This not only validates the effect of the proposed algorithm, but also enriches and improves the research results of UAV path planning.

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A Multi-level Monitoring Framework for Stream-Based Coordination Programs

Algorithms and Architectures for Parallel Processing - Lecture Notes in Computer Science ◽

10.1007/978-3-642-33078-0_7 ◽

2012 ◽

pp. 83-98 ◽

Cited By ~ 3

Author(s):

Vu Thien Nga Nguyen ◽

Raimund Kirner ◽

Frank Penczek

Keyword(s):

Monitoring Framework ◽

Multi Level ◽

Level Monitoring

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Three dimensional numerical modeling using a multi-level nesting system for identifying a Water layer suitable for scallop farming in Tongyeong, Korea

Aquacultural Engineering ◽

10.1016/j.aquaeng.2020.102058 ◽

2020 ◽

Vol 89 ◽

pp. 102058

Author(s):

Yeon S. Chang ◽

Jae-Youll Jin ◽

Jin Yong Choi ◽

Weon Mu Jeong ◽

Sang Kwon Hyun ◽

...

Keyword(s):

Numerical Modeling ◽

Three Dimensional ◽

Water Layer ◽

Multi Level

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Multi-level radio tomographic imaging based three-dimensional static body posture sensing

2016 35th Chinese Control Conference (CCC) ◽

10.1109/chicc.2016.7554699 ◽

2016 ◽

Author(s):

Tong Liu ◽

Zhuo-qian Liang ◽

Jun Liu ◽

Xiao-mu Luo

Keyword(s):

Three Dimensional ◽

Tomographic Imaging ◽

Body Posture ◽

Multi Level ◽

Radio Tomographic Imaging ◽

Static Body

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Image Based Simulation of Pulmonary Airflow Using Multi-Level Voxel Modeling

ASME 2007 Summer Bioengineering Conference ◽

10.1115/sbc2007-176529 ◽

2007 ◽

Author(s):

Yohsuke Imai ◽

Takahito Miki ◽

Masanori Nakamura ◽

Takuji Ishikawa ◽

Shigeo Wada ◽

...

Keyword(s):

Fluid Dynamics ◽

Airflow Obstruction ◽

Three Dimensional ◽

Patient Specific ◽

Chronic Obstructive ◽

Local Domain ◽

Local Flow ◽

Obstructive Pulmonary Disease ◽

Multi Level ◽

Cfd Method

Chronic Obstructive Pulmonary Disease (COPD) refers to a group of diseases that are characterized by airflow obstruction. Currently, COPD is the fourth leading cause of death worldwide, but fluid dynamics in airways of COPD patients has not been well understood. Multi-slice Computer Tomography (CT) images provide three-dimensional realistic geometry of patient airways. Computational Fluid Dynamics (CFD) analysis using the patient-specific geometry will greatly help the understanding of the mechanism of COPD. However, few studies have performed such a patient-specific pulmonary airflow simulation. Our aim is to develop a patient-specific CFD method applicable to multi-scale airways, involving trachea, bronchi, bronchioles, and alveoli. We propose a CFD method using multi-level voxel modeling of airway geometry, in which voxel size in a local domain is adaptively refined or coarsened to the local flow scale.

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The Design of Multi-Level Interrupt Virtual Experiment Based on Object-Oriented

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.171-172.596 ◽

2010 ◽

Vol 171-172 ◽

pp. 596-599

Author(s):

Zhi Hui Wang ◽

Shang Fu Hao ◽

Yuan Qiang Wang

Keyword(s):

Virtual Environment ◽

Discrete Event ◽

Three Dimensional ◽

Object Oriented ◽

Simulation Method ◽

Computer Hardware ◽

Virtual Experiment ◽

Virtual Reality Technology ◽

Multi Level ◽

Computer Organization

The virtual reality technology is a three-dimensional virtual environment composed by computer hardware, software and various of sensors. It creates an unprecedented wealth of content and more fantastic teaching environment which reflects strong advantage in experiment and practice. In accordance with the needs of experiment teaching, multi-level interrupt virtual experiment environment is studied combining with the characteristics of its principle. The experiment environment is based on Tec-xp test box designed and developed by Tsinghua University computer factory. Microsoft Visual C++6.0 language is adopted for software platform development. Seen from the system needs analysis, object-oriented simulation method is adopted for modeling in this experiment environment. Meanwhile combining with computer system features and the characteristics of Computer Organization Principle teaching, the basic theory and methods of discrete event system simulation are used, which make the operation of virtual environment the same as on real device.

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THE UPWARD CONTINUATION OF ANOMALIES IN TOTAL MAGNETIC INTENSITY FIELDS

Geophysics ◽

10.1190/1.1437560 ◽

1949 ◽

Vol 14 (4) ◽

pp. 517-534 ◽

Cited By ~ 44

Author(s):

Roland G. Henderson ◽

Isidore Zietz

Keyword(s):

Three Dimensional ◽

Magnetic Intensity ◽

Mathematical Basis ◽

Upward Continuation ◽

Multi Level

In airborne magnetometry consideration must be given to the necessity of multi‐level observations. The problem of computing total intensity anomalies from data observed on lower levels is investigated in the case of contours exhibiting both two‐ and three‐dimensional features. It is found that even fairly complex anomalies can be extended, with results differing but slightly from observations at the higher level. Maps for comparing computed and observed anomalies are presented. The mathematical basis is given together with numerical formulas and procedures for affecting the computations.

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