scholarly journals Computing the trajectories for the development of optimal routes

2020 ◽  
Author(s):  
M. Fawad Zazai ◽  
Armin R. Fügenschuh
Keyword(s):  
Minimum Distance ◽  
Optimization Problem ◽  
Shortest Paths ◽  
Power Lines ◽  
Dijkstra Algorithm ◽  
Shortest Path Algorithm ◽  
Construction Costs ◽  
New Approach ◽  
Transit Routes ◽  
Absolute Altitude

Abstract Planning the construction of new transport routes or power lines on terrain is usually carried out manually by engineers, with no guarantee of optimality. We introduce a new approach for the computation of an optimal trajectory for the construction of new transit routes and power lines between two locations on a submanifold $$U\subset \mathbb {R}^{3}$$ U ⊂ R 3 representing the topography of a terrain. U is approximatively modeled by a special weighted grid. On this grid, the shortest paths for the construction of new routes are determined, whereby we consider three optimization criteria: routes with minimum distance, routes with lowest construction costs and routes with minimum absolute altitude variations or minimum absolute gradients. Subsequently, a combination of these criteria is used to expand this problem into a multi-criteria optimization problem. A shortest path algorithm, such as the Dijkstra algorithm, is used to compute optimal compromises for the construction of new routes.

Utilizing Restricted Direction Strategy and Binary Heap Technology to Optimize Dijkstra Algorithm in WebGIS

2009 ◽  
Vol 419-420 ◽  
pp. 557-560 ◽  
Author(s):  
Rui Li
Keyword(s):  
Shortest Path ◽  
Operating Efficiency ◽  
Dijkstra Algorithm ◽  
Shortest Path Algorithm ◽  
Research Focus ◽  
Network Information ◽  
The Core ◽  
Highway Network ◽  
Core Issue ◽  
Storage Structures

Shortest path is the core issue in application of WebGIS. Improving the efficiency of the algorithm is an urgent requirement to be resolved at present. By the lossy algorithm analyzing, which is the current research focus of the shortest path algorithm to optimize, utilizing adjacency table of storage structures, restricted direction strategy and binary heap technology to optimize the algorithm, thereby reduce the scale of algorithm to improve the operating efficiency of algorithm. This scheme has been applied in the simulation of the data downloaded from the Guangdong Provincial Highway Network Information System and satisfactory results have been obtained.

scholarly journals MODELING OF EMERGENCY EVACUATION IN BUILDING FIRE

2020 ◽  
Vol XLIII-B4-2020 ◽  
pp. 321-327 ◽  
Author(s):  
H. Bayat ◽  
M. R. Delavar ◽  
W. Barghi ◽  
S. A. EslamiNezhad ◽  
P. Hanachi ◽  
...  
Keyword(s):  
Indoor Environment ◽  
Shortest Paths ◽  
Fire Risk ◽  
Emergency Evacuation ◽  
Information Modeling ◽  
Sufficient Information ◽  
Dijkstra Algorithm ◽  
Rescue Workers ◽  
Building Information ◽  
Emergency Exit

Abstract. One of the main problems of rescue workers in confrontation of fired complex buildings is the lack of sufficient information about the building indoor environment and their emergency exit ways. Building information modeling (BIM) is a database for building a 3D model of building information to create a 3D building geometry network model. This paper has implemented some GIS and BIM integration analyses to determine the shortest and safest paths to people under fire risk and simulate their movement in the building. Plasco building was a multi-story shop in Tehran which has been fired in 2017 and destroyed. This paper attempts to simulate the firefighting and rescue operations in Plasco Building using an integration of BIM and GIS. There is no detailed information about the building and the fire incident, therefore the developed BIM and corresponding geometric network might differ slightly. The shortest and safest paths to the exit door or windows where the fire ladders are located are computed and analyzed. As a result of 15 scenarios developed in this paper, it was found that at 87% of the cases, the safest paths for the emergency exit of the people at risk were longer than the shortest paths. This study has evaluated different scenarios for the shortest and safest paths using Dijkstra algorithm considering different origins and destination points in the 3D indoor environment to assist the rescue operations.

scholarly journals Control Force Recalculation for Balancing Problems

2019 ◽  
Vol 19 (05) ◽  
pp. 1941010
Author(s):  
Bálint Bodor ◽  
László Bencsik ◽  
Tamás Insperger
Keyword(s):  
Optimization Problem ◽  
Control Mechanism ◽  
Numerical Differentiation ◽  
Open Loop ◽  
Second Step ◽  
Control Force ◽  
New Approach ◽  
Numerical Errors ◽  
Linearized System ◽  
Control Forces

Understanding the mechanism of human balancing is a scientifically challenging task. In order to describe the nature of the underlying control mechanism, the control force has to be determined experimentally. A main feature of balancing tasks is that the open-loop system is unstable. Therefore, reconstruction of the trajectories using the measured control force is difficult, since measurement inaccuracies, noise and numerical errors increase exponentially with time. In order to overcome this problem, a new approach is proposed in this paper. In the presented technique, first the solution of the linearized system is used. As a second step, an optimization problem is solved which is based on a variational principle. A main advantage of the method is that there is no need for the numerical differentiation of the measured data for the calculation of the control forces, which is the main source of the numerical errors. The method is demonstrated in case of a human stick balancing.

scholarly journals A General Framework for Portfolio Theory. Part III: Multi-Period Markets and Modular Approach

Risks ◽  
2019 ◽  
Vol 7 (2) ◽  
pp. 60
Author(s):  
Stanislaus Maier-Paape ◽  
Andreas Platen ◽  
Qiji Jim Zhu
Keyword(s):  
General Framework ◽  
Optimization Problem ◽  
Risk Measure ◽  
Efficient Frontier ◽  
Portfolio Theory ◽  
Trading Strategies ◽  
Performance Criteria ◽  
Market Model ◽  
Constant Weight ◽  
New Approach

This is Part III of a series of papers which focus on a general framework for portfolio theory. Here, we extend a general framework for portfolio theory in a one-period financial market as introduced in Part I [Maier-Paape and Zhu, Risks 2018, 6(2), 53] to multi-period markets. This extension is reasonable for applications. More importantly, we take a new approach, the “modular portfolio theory”, which is built from the interaction among four related modules: (a) multi period market model; (b) trading strategies; (c) risk and utility functions (performance criteria); and (d) the optimization problem (efficient frontier and efficient portfolio). An important concept that allows dealing with the more general framework discussed here is a trading strategy generating function. This concept limits the discussion to a special class of manageable trading strategies, which is still wide enough to cover many frequently used trading strategies, for instance “constant weight” (fixed fraction). As application, we discuss the utility function of compounded return and the risk measure of relative log drawdowns.

Optimal Viscous Damper Placement Using Level Set Topology Optimization Method

2010 ◽  
Author(s):  
Masoud Ansari ◽  
Amir Khajepour ◽  
Ebrahim Esmailzadeh
Keyword(s):  
Topology Optimization ◽  
Level Set ◽  
Discrete Optimization ◽  
Optimization Problem ◽  
Minimum Energy ◽  
Optimization Method ◽  
Discrete Optimization Problem ◽  
Placement Problem ◽  
New Approach ◽  
Optimal Damping

Vibration control has always been of great interest for many researchers in different fields, especially mechanical and civil engineering. One of the key elements in control of vibration is damper. One way of optimally suppressing unwanted vibrations is to find the best locations of the dampers in the structure, such that the highest dampening effect is achieved. This paper proposes a new approach that turns the conventional discrete optimization problem of optimal damper placement to a continuous topology optimization. In fact, instead of considering a few dampers and run the discrete optimization problem to find their best locations, the whole structure is considered to be connected to infinite numbers of dampers and level set topology optimization will be performed to determine the optimal damping set, while certain number of dampers are used, and the minimum energy for the system is achieved. This method has a few major advantages over the conventional methods, and can handle damper placement problem for complicated structures (systems) more accurately. The results, obtained in this research are very promising and show the capability of this method in finding the best damper location is structures.

scholarly journals Orthogonal distance from an ellipsoid

2014 ◽  
Vol 20 (4) ◽  
pp. 970-983 ◽  
Author(s):  
Sebahattin Bektas
Keyword(s):  
Computer Games ◽  
Minimum Distance ◽  
Optimization Problem ◽  
Physical Reality ◽  
Triaxial Ellipsoid ◽  
Ellipsoidal Height ◽  
Scientific Investigations ◽  
The Earth ◽  
Shortest Distance ◽  
Geodetic Coordinate Transformation

Finding the orthogonal (shortest) distance to an ellipsoid corresponds to the ellipsoidal height in Geodesy. Despite that the commonly used Earth reference systems, like WGS-84, are based on rotational ellipsoids, there have also been over the course of the years permanent scientific investigations undertaken into different aspects of the triaxial ellipsoid. Geodetic research has traditionally been motivated by the need to approximate closer and closer the physical reality. Several investigations have shown that the earth is approximated better by a triaxial ellipsoid rather than a rotational one Burša and Šima (1980). The problem of finding the shortest distance is encountered frequently in the Cartesian- Geodetic coordinate transformation, optimization problem, fitting ellipsoid, image processing, face recognition, computer games, and so on. We have chosen a triaxial ellipsoid for the reason that it possesess a general surface. Thus, the minimum distance from rotational ellipsoid and sphere is found with the same algorithm. This study deals with the computation of the shortest distance from a point to a triaxial ellipsoid.

New approach for power lines performance estimation based on load variation due to voltage sags

2012 ◽  
Vol 83 (1) ◽  
pp. 35-40 ◽  
Author(s):  
Roberto Chouhy Leborgne ◽  
Thiago Clé de Oliveira ◽  
José Maria de Carvalho Filho ◽  
Jeder Francisco de Oliveira ◽  
Math H.J. Bollen
Keyword(s):  
Performance Estimation ◽  
Power Lines ◽  
Voltage Sags ◽  
New Approach ◽  
Load Variation

An Efficient K-Shortest Paths Based Routing Algorithm

2012 ◽  
Vol 532-533 ◽  
pp. 1775-1779
Author(s):  
Jian Lian ◽  
Yan Zhang ◽  
Cheng Jiang Li
Keyword(s):  
Computer Networks ◽  
Shortest Path ◽  
Traffic Engineering ◽  
Routing Algorithm ◽  
Shortest Paths ◽  
Routing Algorithms ◽  
Dijkstra Algorithm ◽  
Link State

We present an efficient K-shortest paths routing algorithm for computer networks. This Algorithm is based on enhancements to currently used link-state routing algorithms such as OSPF and IS-IS, which are only focusing on finding the shortest path route by adopting Dijkstra algorithm. Its desire effect to achieve is through the use of K-shortest paths algorighm, which has been implemented successfully in some fileds like traffic engineering. The correctness of this Algorithm is discussed at the same time as long as the comparison with OSPF.

scholarly journals Distance closures on complex networks

2015 ◽  
Vol 3 (2) ◽  
pp. 227-268 ◽  
Author(s):  
TIAGO SIMAS ◽  
LUIS M. ROCHA
Keyword(s):  
Complex Networks ◽  
Diffusion Processes ◽  
Shortest Paths ◽  
Approximate Reasoning ◽  
Weighted Graphs ◽  
Dijkstra Algorithm ◽  
Simple Method ◽  
Distance Graphs ◽  
Network Analyses ◽  
Metric Distances

AbstractTo expand the toolbox available to network science, we study the isomorphism between distance and Fuzzy (proximity or strength) graphs. Distinct transitive closures in Fuzzy graphs lead to closures of their isomorphic distance graphs with widely different structural properties. For instance, the All Pairs Shortest Paths (APSP) problem, based on the Dijkstra algorithm, is equivalent to a metric closure, which is only one of the possible ways to calculate shortest paths in weighted graphs. We show that different closures lead to different distortions of the original topology of weighted graphs. Therefore, complex network analyses that depend on the calculation of shortest paths on weighted graphs should take into account the closure choice and associated topological distortion. We characterize the isomorphism using the max-min and Dombi disjunction/conjunction pairs. This allows us to: (1) study alternative distance closures, such as those based on diffusion, metric, and ultra-metric distances; (2) identify the operators closest to the metric closure of distance graphs (the APSP), but which are logically consistent; and (3) propose a simple method to compute alternative path length measures and corresponding distance closures using existing algorithms for the APSP. In particular, we show that a specific diffusion distance is promising for community detection in complex networks, and is based on desirable axioms for logical inference or approximate reasoning on networks; it also provides a simple algebraic means to compute diffusion processes on networks. Based on these results, we argue that choosing different distance closures can lead to different conclusions about indirect associations on network data, as well as the structure of complex networks, and are thus important to consider.

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