scholarly journals A Study on a Matching Algorithm for Urban Underground Pipelines

2019 ◽  
Vol 8 (8) ◽  
pp. 352
Author(s):  
Shuai Wang ◽  
Qingsheng Guo ◽  
Xinglin Xu ◽  
Yuwu Xie
Keyword(s):  
Blood Vessels ◽  
Underground Pipeline ◽  
Matching Algorithm ◽  
Partial Matching ◽  
Spatial Objects ◽  
Operation Efficiency ◽  
Geometric Similarity ◽  
Underground Pipelines ◽  
Pipeline Networks ◽  
Matching Performance

Urban underground pipelines are known as “urban blood vessels”. To detect changes in integrated pipelines and professional pipelines, the matching of same-name spatial objects is critical. Existing algorithms used for vector network matching were analyzed to develop an improved matching algorithm that can adapt to underground pipeline networks. Our algorithm improves the holistic matching of pipeline strokes, and also a partial matching algorithm is provided. In this study, appropriate geometric measures were selected to calculate the geometric similarity between pipeline strokes in their holistic matching. Existing methods for evaluating similarities in spatial scene structures in partial underground pipeline networks were improved. A method of partial matching of strokes was additionally investigated, and it compensates for the deficiencies of holistic stroke matching. Experiments showed that the matching performance was good, and the operation efficiency was high.

scholarly journals Weak factor automata: the failure of failure factor oracles?

2014 ◽  
Vol 53 ◽  
Author(s):  
Loek Cleophas ◽  
Derrick G. Kourie ◽  
Bruce W. Watson
Keyword(s):  
Pattern Matching ◽  
Dna Sequences ◽  
Finite Automata ◽  
Compact Representation ◽  
Data Sets ◽  
Matching Algorithm ◽  
Weak Factor ◽  
Ex Post ◽  
Ex Post Facto ◽  
Matching Performance

In indexing of, and pattern matching on, DNA and text sequences, it is often important to represent all factors of a sequence. One efficient, compact representation is the factor oracle (FO). At the same time, any classical deterministic finite automata (DFA) can be transformed to a so-called failure one (FDFA), which may use failure transitions to replace multiple symbol transitions, potentially yielding a more compact representation. We combine the two ideas and directly construct a failure factor oracle (FFO) from a given sequence, in contrast to ex post facto transformation to an FDFA. The algorithm is suitable for both short and long sequences. We empirically compared the resulting FFOs and FOs on number of transitions for many DNA sequences of lengths 4 − 512, showing gains of up to 10% in total number of transitions, with failure transitions also taking up less space than symbol transitions. The resulting FFOs can be used for indexing, as well as in a variant of the FO-using backward oracle matching algorithm. We discuss and classify this pattern matching algorithm in terms of the keyword pattern matching taxonomies of Watson, Cleophas and Zwaan. We also empirically compared the use of FOs and FFOs in such backward reading pattern matching algorithms, using both DNA and natural language (English) data sets. The results indicate that the decrease in pattern matching performance of an algorithm using an FFO instead of an FO may outweigh the gain in representation space by using an FFO instead of an FO.

The Design and Establishment of 3D Urban Underground Pipeline Plan Aid System

2013 ◽  
Vol 475-476 ◽  
pp. 1546-1550
Author(s):  
Ying Chun Tao ◽  
Lian Zhao ◽  
Guo Jiang Zheng ◽  
Bo Gang Yang
Keyword(s):  
Decision Making ◽  
Normal Operation ◽  
Underground Pipeline ◽  
Planning Commission ◽  
Municipal Planning ◽  
Pipeline Network ◽  
Scene Graph ◽  
Underground Pipelines ◽  
The City ◽  
Modelling Process

Urban underground pipelines are the lifelines of the city. With the acceleration of city modernization, the traditional way to design and manage pipeline plans which relies on 2D diagrams has been difficult to secure the normal operation of the city. In this paper, a standard automatic 3D pipeline modelling process is proposed; a way to manage massive 3D scenes by scene graph is raised; three patterns of 3D integrated visualization are suggested; innovative stereo displays of pipeline analysis results are thought out. Eventually, a 3D urban underground pipeline plan aid system has been developed. At present, the system has been used in Xicheng Bureau of the Beijing Municipal Planning Commission, providing valuable decision-making information for urban underground pipeline network planning and management.

Method for laying underground pipelines taking into account the danger of landslide processes

2021 ◽  
pp. 16-20
Author(s):  
Хабиб Миргалиб оглы Насиров ◽  
Тофик Инаят оглы Сулейманов ◽  
Рамиз Ахмед оглы Эминов
Keyword(s):  
Calculation Method ◽  
Landslide Hazard ◽  
Low Risk ◽  
Segment Length ◽  
Underground Pipeline ◽  
Landslide Activity ◽  
Underground Pipelines ◽  
Landslide Processes ◽  
Pipeline Design

Известная расчетная методика оценки риска воздействия оползневых процессов на подземный трубопровод позволяет вычислить количество возможных утечек и поломок, исходно приняв данный риск равным для всех равноразмерных отрезков трубопровода. Однако на практике равная степень подверженности оползневой опасности участков трубопровода является исключением. Таким образом, возникает необходимость разработки новой методики расчета, предусматривающей реальные условия проектирования и эксплуатации трубопровода. Авторами определено условие, при котором подверженность трубопровода утечкам и разрывам в результате воздействия оползневых процессов может достигать максимальных значений. Сделан вывод о том, что для обеспечения разумной низкой величины риска следует избегать выполнения полученной зависимости. При этом должны быть соблюдены следующие условия: трасса разделена на неравные отрезки, с увеличением длины отрезка пиковая скорость грунта убывает (то есть более протяженные участки трубопровода следует располагать вдали от зон возможной активности оползневых процессов). The well-known calculation method for assessing the risk of landslide impact on an underground pipeline makes it possible to calculate the number of possible leaks and breakdowns, initially assuming an equal risk for all equally sized pipeline sections. However, in practice, equal exposure to landslide hazard of pipeline sections is an exception. Thus, there is a need to develop a new calculation method that provides for real conditions for pipeline design and operation. The authors determined the condition under which pipeline susceptibility to leaks and ruptures as a result of landslide impact can reach maximum values. It is concluded that in order to ensure a reasonably low risk value, the implementation of the resulting dependence should be avoided. In this case, the following conditions must be met: the route is divided into unequal segments, with an increase in segment length, the peak soil velocity decreases (that is, longer pipeline sections should be located away from possible landslide activity zones).

Reliability based life cycle cost optimization for underground pipeline networks

2014 ◽  
Vol 43 ◽  
pp. 32-40 ◽  
Author(s):  
Kong Fah Tee ◽  
Lutfor Rahman Khan ◽  
Hua Peng Chen ◽  
Amir M. Alani
Keyword(s):  
Life Cycle ◽  
Life Cycle Cost ◽  
Cost Optimization ◽  
Underground Pipeline ◽  
Pipeline Networks

New Environmental Line Feature-based Vision Navigation: Design and Analysis

2017 ◽  
Vol 70 (5) ◽  
pp. 1133-1152
Author(s):  
Zeyu Li ◽  
Jinling Wang ◽  
Kai Chen ◽  
Yu Sun
Keyword(s):  
Feature Matching ◽  
Point Matching ◽  
Vision Navigation ◽  
Matching Algorithm ◽  
Environmental Features ◽  
Feature Based ◽  
Matching Performance ◽  
New Feature ◽  
Point To Point ◽  
Local Gradient

Vision navigation using environmental features has been widely applied when satellite signals are not available. However, the matching performance of traditional environmental features such as keypoints degrades significantly in weakly textured areas, deteriorating navigation performance. Further, the user needs to evaluate and assure feature matching quality. In this paper, a new feature, named Line Segment Intersection Feature (LSIF), is proposed to solve the availability problem in weakly textured regions. Then a combined descriptor involving global structure and local gradient is designed for similarity comparison. To achieve reliable point-to-point matching, a coarse-to-fine matching algorithm is developed, which improves the performance of the point set matching algorithm. Finally, a framework of matching quality evaluation is proposed to assure matching performance. Through the comparison, it is demonstrated that the proposed new feature has superior overall performance especially on correctly matched numbers of keypoints and matching correctness. Also, using real image sets with weak texture, it is shown that the proposed LSIF can achieve improved navigation solutions with high continuity and accuracy.

Study on Influence of Tunnel Excavation on Seismic Performance of Underground Pipeline

2011 ◽  
Vol 90-93 ◽  
pp. 1801-1806
Author(s):  
Run Lin Yang ◽  
Tian Yuan Zhang
Keyword(s):  
Ground Motion ◽  
Seismic Performance ◽  
Seismic Action ◽  
Underground Pipeline ◽  
Buried Pipelines ◽  
Tunnel Excavation ◽  
Modeling And Analysis ◽  
Underground Pipelines ◽  
Earthquake Resistant ◽  
Before And After

It is often necessary to study on the seismic performance of the buried pipelines subjected to tunnel excavation, because the ground motion will inevitably endanger the nearby underground pipelines. In this paper, modeling and analysis of earthquake-resistant performance of tunnel excavation to the upper underground pipeline have been carried out. The changes of stress and displacement of the upper underground pipeline under action of the same seismic wave before and after tunnel excavation was compared. It is showed that there’s a greater impact on the stress and displacement of upper underground pipeline under seismic action, and a tunnel with reasonable supporting would support the underground pipeline to some extent.

Earthquake Response of Underground Pipeline Networks in Christchurch, NZ

2014 ◽  
Vol 30 (1) ◽  
pp. 183-204 ◽  
Author(s):  
Thomas D. O'Rourke ◽  
Sang-Soo Jeon ◽  
Selcuk Toprak ◽  
Misko Cubrinovski ◽  
Matthew Hughes ◽  
...  
Keyword(s):  
Distribution System ◽  
Distribution Systems ◽  
Ground Surface ◽  
Lessons Learned ◽  
Peak Ground Velocity ◽  
Underground Pipeline ◽  
Gas Distribution ◽  
Pipeline Networks ◽  
Before And After ◽  
Ground Surface Settlement

This paper explores key aspects of underground pipeline network response to the Canterbury earthquake sequence in Christchurch, New Zealand, including the response of the water and wastewater distribution systems to the MW6.2 22 February 2011 and MW6.0 13 June 2011 earthquakes, and the response of the gas distribution system to the MW7.1 4 September 2010 earthquake, as well as the 22 February and 13 June events. Repair rates, expressed as repairs/km, for different types of pipelines are evaluated relative to (1) the spatial distribution of peak ground velocity outside liquefaction areas and (2) the differential ground surface settlement and lateral ground strain within areas affected by liquefaction, calculated from high-resolution LiDAR survey data acquired before and after each main seismic event. The excellent performance of the gas distribution network is the result of highly ductile polyethylene pipelines. Lessons learned regarding the earthquake performance of underground lifeline systems are summarized.

scholarly journals STATIC STRAINING AND LONGITUDINAL OSCILLATIONS OF UNDERGROUND PIPELINE BUILT ON BLOCK FOUNDATION

2021 ◽  
pp. 123-133
Author(s):  
A. B. Struk ◽  
M. I. Vaskovskyi ◽  
I. P. Shatskyi ◽  
M. V. Makoviichuk
Keyword(s):  
Steady State ◽  
Stress State ◽  
Differential Equations ◽  
Analytical Solutions ◽  
Equivalent Stress ◽  
Forced Oscillations ◽  
Underground Pipeline ◽  
Underground Pipelines ◽  
Block Foundation ◽  
Static Tensile

The article considers the issues of forecasting the strength of underground pipelines, which are operated on seismically active sections of the route, composed of relatively rigid mobile blocks. According to the literature, the problems of the influence of the interaction of base faults on the stress state of the pipeline have not been studied to date. The aim of the work is to develop a model for the analysis of abnormal stresses in the underground pipeline on a damaged basis caused by static or time-harmonious mutual movement of its blocks along the axis of the pipe in the presence of several faults. Boundary value problems for differential equations of static tensile-compression and steady-state longitudinal oscillations of a tubular rod with discontinuous right-hand sides are formulated. Based on the analytical solutions of these problems for the cases of antisymmetric and symmetric displacement of the foundation blocks, the distributions of axial displacement and equivalent stress in the pipe, depending on the distance between faults and the frequency of forced oscillations, are investigated.

scholarly journals Design of Natural Gas Pipeline

2021 ◽  
Vol 9 (VIII) ◽  
pp. 733-737
Author(s):  
Ashwini Chavan
Keyword(s):  
Fossil Fuel ◽  
Distribution Networks ◽  
End Users ◽  
Automotive Sector ◽  
Gas Distribution ◽  
Industrial Enterprises ◽  
Underground Pipelines ◽  
Metropolitan Cities ◽  
Pipeline Networks ◽  
City Gas

India today has an in depth network of underground pipelines used for the transportation and distribution of gas. Large factories, fertilizer factories and other industrial enterprises are the most consumers in PNG and today, however, with the rise in its popularity, it's currently utilized in the domestic sector similarly as a fuel within the automotive sector in large metropolitan cities. To bring gas to those end users within the boundaries of a significant city, it's necessary to create city gas distribution pipeline networks. India today has an intensive network of underground pipelines used for the transportation and distribution of fossil fuel. Large factories, fertilizer factories and other industrial enterprises are the most consumers in PNG and today, however, with the rise in its popularity, it's currently employed in the domestic sector additionally as a fuel within the automotive sector in large metropolitan cities. To bring gas to those end users within the boundaries of a significant city, it's necessary to create city gas distribution pipeline networks, these networks have already been founded within the cities of Delhi, Mumbai, Vadodara, Firozabad, Kanpur and plenty of more such networks are planned within the near future. Given the infrastructure and layout available in typical Indian cities, it becomes difficult to make such gas distribution networks without separate corridors for competing utilities. Reckoning on pressures, flow rates and economic criteria, these networks may be constructed with steel pipes, polyethylene (PE) pipes or a hybrid PE-steel pipe system. In contrast to borehole pipelines, which stretch for miles directly through open fields, the CGD network is more complex. These are located in densely populated areas, and an oversized number of network branches meet the wants of users in several locations in an exceedingly city. Although they're much smaller long and size than background pipelines, a city's network is far more dispersed and diverse. The rise within the number of branches means over the amount of sleeves, bends, reducers, fittings, etc. within the network, with the exception of the quantity of delivery points for the availability of fossil fuel. Due to the assorted activities of third parties other city agencies, the chance of injury and accidents is even on top of the substantial pipelines. of these factors require better security systems integrated into the network and therefore the need for special preparation to manage any emergency situation.

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