scholarly journals The Optimization Model of Composite Material UAV Shooting Flight Routes

CONVERTER ◽  
2021 ◽  
pp. 698-717
Author(s):  
Ting Zheng

UAV is one of the important achievements of scientific and technological innovation, which has been widely used in various fields of life in recent years. UAVs of composite materials are the most popular because the composite itself has designability, and can be optimized according to the strength and stiffness of the aircraft without changing the structural weight. In order to ensure the UAV to carry out more accurate image acquisition under the actual ground conditions, through the analysis of decision variables, this paper uses the linear weighting of image shooting range and pixel accuracy to establish the objective function, and establishes the optimal shooting angle under different constraints Considering the actual motion characteristics of objects such as automobiles, this paper assumes that the tracked ground targets are a class of motion objects with non-integrity constraints when the flight altitude of UAV is fixed and the flight speed is constant. The ground target model and the flight dynamics nonlinear model are established. This paper presents a new RRT* algorithm for path planning based on the obstacles encountered by UAV during flight, that is, using the cost function to select the node with the minimum cost in the field of expanding nodes as the parent node, using the MATLAB to select a reasonable obstacle avoidance strategy, the global optimal route is obtained by smoothing processing, and the data simulation test is carried out. The experimental results show that the model is robust.

Author(s):  
J. C. Cripps ◽  
P. B. Attewell ◽  
J. P. Woodman

AbtractPlanning the development of an urban area is a complex operation in which many disparate objectives and constraints must be reconciled. An attempt is usually made to achieve particular aims at minimum cost. If geological and geotechnical factors are considered in isolation, then a particular structure will cost least to build in locations offering the most favourable ground conditions. Unfortunately, seldom is suitable geological and geotechnical information available at this early stage of development.The paper outlines a mechanism whereby reduction in the uncertainty about the ground conditions, achieved by carrying out site investigations work, may be related, through the application of simple probability theory, to a consequent expected loss caused by construction or maintenance. Thus in planning decisions a financial optimum can be identified in which the cost implications of ground investigations, construction and maintenance can be taken into account.


2020 ◽  
Vol 54 (6) ◽  
pp. 1775-1791
Author(s):  
Nazila Aghayi ◽  
Samira Salehpour

The concept of cost efficiency has become tremendously popular in data envelopment analysis (DEA) as it serves to assess a decision-making unit (DMU) in terms of producing minimum-cost outputs. A large variety of precise and imprecise models have been put forward to measure cost efficiency for the DMUs which have a role in constructing the production possibility set; yet, there’s not an extensive literature on the cost efficiency (CE) measurement for sample DMUs (SDMUs). In an effort to remedy the shortcomings of current models, herein is introduced a generalized cost efficiency model that is capable of operating in a fuzzy environment-involving different types of fuzzy numbers-while preserving the Farrell’s decomposition of cost efficiency. Moreover, to the best of our knowledge, the present paper is the first to measure cost efficiency by using vectors. Ultimately, a useful example is provided to confirm the applicability of the proposed methods.


2020 ◽  
Vol 26 (3) ◽  
pp. 685-697
Author(s):  
O.V. Shimko

Subject. The study analyzes generally accepted approaches to assessing the value of companies on the basis of financial statement data of ExxonMobil, Chevron, ConocoPhillips, Occidental Petroleum, Devon Energy, Anadarko Petroleum, EOG Resources, Apache, Marathon Oil, Imperial Oil, Suncor Energy, Husky Energy, Canadian Natural Resources, Royal Dutch Shell, Gazprom, Rosneft, LUKOIL, and others, for 1999—2018. Objectives. The aim is to determine the specifics of using the methods of cost, DFC, and comparative approaches to assessing the value of share capital of oil and gas companies. Methods. The study employs methods of statistical analysis and generalization of materials of scientific articles and official annual reports on the results of financial and economic activities of the largest public oil and gas corporations. Results. Based on the results of a comprehensive analysis, I identified advantages and disadvantages of standard approaches to assessing the value of oil and gas producers. Conclusions. The paper describes pros and cons of the said approaches. For instance, the cost approach is acceptable for assessing the minimum cost of small companies in the industry. The DFC-based approach complicates the reliability of medium-term forecasts for oil prices due to fluctuations in oil prices inherent in the industry, on which the net profit and free cash flow of companies depend to a large extent. The comparative approach enables to quickly determine the range of possible value of the corporation based on transactions data and current market situation.


Author(s):  
José-Manuel Giménez-Gómez ◽  
Josep E. Peris ◽  
Begoña Subiza

2019 ◽  
Vol 49 (1) ◽  
pp. 327-359 ◽  
Author(s):  
Alan Taub ◽  
Emmanuel De Moor ◽  
Alan Luo ◽  
David K. Matlock ◽  
John G. Speer ◽  
...  

Reducing the weight of automobiles is a major contributor to increased fuel economy. The baseline materials for vehicle construction, low-carbon steel and cast iron, are being replaced by materials with higher specific strength and stiffness: advanced high-strength steels, aluminum, magnesium, and polymer composites. The key challenge is to reduce the cost of manufacturing structures with these new materials. Maximizing the weight reduction requires optimized designs utilizing multimaterials in various forms. This use of mixed materials presents additional challenges in joining and preventing galvanic corrosion.


2012 ◽  
Vol 472-475 ◽  
pp. 3273-3276
Author(s):  
Qing Ying Zhang ◽  
Ying Chi ◽  
Yu Liu ◽  
Qian Shi

The main target of supply chain management is to control inventory of each node enterprise effectively with the minimum cost. In this paper, the control strategies and methods of inventory based on supply chain management are put forward, which are significant for saving the cost of supply chain and improving the overall benefits of the whole chain.


2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
K. N. Lakshmikandhan ◽  
P. Sivakumar ◽  
R. Ravichandran ◽  
S. Arul Jayachandran

The strength of the composite deck slab depends mainly on the longitudinal shear transfer mechanism at the interface between steel and concrete. The bond strength developed by the cement paste is weak and causes premature failure of composite deck slab. This deficiency is effectively overcame by a shear transferring mechanism in the form of mechanical interlock through indentations, embossments, or fastening studs. Development of embossment patterns requires an advanced technology which makes the deck profile expensive. Fastening studs by welding weakens the joint strength and also escalates the cost. The present investigation is attempted to arrive at a better, simple interface mechanism. Three types of mechanical connector schemes are identified and investigated experimentally. All of the three shear connector schemes exhibited full shear interaction with negligible slip. The strength and stiffness of the composite slabs with shear connectors are superior about one and half time compared to these of the conventional reinforced concrete slabs and about twice compared to these of composite slabs without mechanical shear connectors. The scheme2 and scheme3 shear connector mechanisms integrate deck webs and improve strength and stiffness of the deck, which can effectively reduce the cost of formworks and supports efficiently.


1979 ◽  
Vol 6 (1) ◽  
pp. 120-128
Author(s):  
Craig J. Miller ◽  
Juarez Accioly

Precast, prestressed segmental box-girder bridges are now accepted as an economical alternative for spans over 150 ft (46 m). Decisions about cross-sectional dimensions made during preliminary design can have a substantial influence on the final cost of the bridge. To help the designer obtain an economical starting point for a final design, a program was written to determine section dimensions and midspan and pier prestressing steel areas to give minimum cost. Since a preliminary design is obtained, the analysis techniques and design criteria have been simplified to reduce computation. The design produced by the program will satisfy AASHTO specification requirements and the recommendations of the PCI Bridge Committee. The optimization algorithm used is the generalized reduced gradient technique. To demonstrate the program capabilities, three example problems are discussed. The results indicate that optimum span-depth ratios are approximately 24 for the cost ratios used. The cost of the optimum design does not seem to be too sensitive to the ratio of concrete cost to prestressing steel cost.


2018 ◽  
Vol 25 (4) ◽  
pp. 28
Author(s):  
Christina Burt ◽  
Alysson Costa ◽  
Charl Ras

We study the problem of constructing minimum power-$p$ Euclidean $k$-Steiner trees in the plane. The problem is to find a tree of minimum cost spanning a set of given terminals where, as opposed to the minimum spanning tree problem, at most $k$ additional nodes (Steiner points) may be introduced anywhere in the plane. The cost of an edge is its length to the power of $p$ (where $p\geq 1$), and the cost of a network is the sum of all edge costs. We propose two heuristics: a ``beaded" minimum spanning tree heuristic; and a heuristic which alternates between minimum spanning tree construction and a local fixed topology minimisation procedure for locating the Steiner points. We show that the performance ratio $\kappa$ of the beaded-MST heuristic satisfies $\sqrt{3}^{p-1}(1+2^{1-p})\leq \kappa\leq 3(2^{p-1})$. We then provide two mixed-integer nonlinear programming formulations for the problem, and extend several important geometric properties into valid inequalities. Finally, we combine the valid inequalities with warm-starting and preprocessing to obtain computational improvements for the $p=2$ case.


Author(s):  
Derek Yip-Hoi ◽  
Debasish Dutta

Abstract Changing worn tools is a major concern in planning operations on machining systems. Strategies for replacing tools range from changing each tool as it reaches its projected tool life, to changing all tools when the tool with the shortest life on the machining system is expended. Intermediate strategies involve changing tools in groups. Each of these strategies has two cost components associated with it: (1) the cost of lost production due to machine tool stoppage, and (2) the cost of unused tool life. The best tool grouping strategy minimizes the combined cost of lost production. In this paper we present an approach for finding good tool grouping strategies from inputs that include the tool utilization for a given machining application, and the tooling and machining system costs. A genetic algorithm is used as the underlying optimization paradigm for finding the minimum cost strategy. An example is presented for a part produced on a machining center.


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