Ship Hull Structural Multiobjective Optimization by Evolutionary Algorithm

2014 ◽  
Vol 58 (02) ◽  
pp. 45-69 ◽  
Author(s):  
Zbigniew Sekulski

An evolutionary algorithm for multiobjective optimization of the structural elements of the large spatial sections of ships is presented. The evolutionary algorithm where selection takes place based on the aggregated objective function combined with domination attributes as well as distance to the asymptotic solution is proposed and applied to solve the problem of optimizing structural elements with respect to their weight and surface area on a high-speed vehicle-passenger catamaran structure with several design variables such as plate thickness, scantlings of longitudinal stiffeners and transverse frames, and spacing between longitudinal and transversal structural members. Details of the computational models were at the level typical for conceptual design. Scantlings were analyzed using the selected rules of a classification society. The results of numerical experiments with the use of the developed algorithm are presented. They show that the proposed genetic algorithm can be a foundation of the effective multiobjective optimization tool for ship structure optimization. Further development of the tool should include more advanced methods for ship structural analysis.

2008 ◽  
Vol 130 (11) ◽  
Author(s):  
Afzal Husain ◽  
Kwang-Yong Kim

A multiobjective performance optimization of microchannel heat sink is carried out numerically applying surrogate analysis and evolutionary algorithm. Design variables related to microchannel width, depth, and fin width are selected, and two objective functions, thermal resistance and pumping power, are employed. With the help of finite volume solver, Navier–Stokes analyses are performed at the design sites obtained from full factorial design of sampling methods. Using the numerically evaluated objective function values, polynomial response surface is constructed for each objective functions, and multiobjective optimization is performed to obtain global Pareto optimal solutions. Analysis of optimum solutions is simplified by carrying out trade-off with design variables and objective functions. Objective functions exhibit changing sensitivity to design variables along the Pareto optimal front.


Author(s):  
Nikolai Petrov ◽  
Nikolai Petrov ◽  
Inna Nikonorova ◽  
Inna Nikonorova ◽  
Vladimir Mashin ◽  
...  

High-speed railway "Moscow-Kazan" by the draft crosses the Volga (Kuibyshev reservoir) in Chuvashia region 500 m below the village of New Kushnikovo. The crossing plot is a right-bank landslide slope with a stepped surface. Its height is 80 m; the slope steepness -15-16o. The authors should assess the risk of landslides and recommend anti-landslide measures to ensure the safety of the future bridge. For this landslide factors have been analyzed, slope stability assessment has been performed and recommendations have been suggested. The role of the following factors have been analyzed: 1) hydrologic - erosion and abrasion reservoir and runoff role; 2) lithologyc (the presence of Urzhum and Northern Dvina horizons of plastically deformable rocks, displacement areas); 3) hydrogeological (the role of perched, ground and interstratal water); 4) geomorphological (presence of the elemental composition of sliding systems and their structure in the relief); 5) exogeodynamic (cycles and stages of landslide systems development, mechanisms and relationship between landslide tiers of different generations and blocks contained in tiers). As a result 6-7 computational models at each of the three engineering-geological sections were made. The stability was evaluated by the method “of the leaning slope”. It is proved that the slope is in a very stable state and requires the following measures: 1) unloading (truncation) of active heads blocks of landslide tiers) and the edge of the plateau, 2) regulation of the surface and groundwater flow, 3) concrete dam, if necessary.


2021 ◽  
Vol 11 (4) ◽  
pp. 1817
Author(s):  
Zheng Li ◽  
Azure Wilson ◽  
Lea Sayce ◽  
Amit Avhad ◽  
Bernard Rousseau ◽  
...  

We have developed a novel surgical/computational model for the investigation of unilat-eral vocal fold paralysis (UVFP) which will be used to inform future in silico approaches to improve surgical outcomes in type I thyroplasty. Healthy phonation (HP) was achieved using cricothyroid suture approximation on both sides of the larynx to generate symmetrical vocal fold closure. Following high-speed videoendoscopy (HSV) capture, sutures on the right side of the larynx were removed, partially releasing tension unilaterally and generating asymmetric vocal fold closure characteristic of UVFP (sUVFP condition). HSV revealed symmetric vibration in HP, while in sUVFP the sutured side demonstrated a higher frequency (10–11%). For the computational model, ex vivo magnetic resonance imaging (MRI) scans were captured at three configurations: non-approximated (NA), HP, and sUVFP. A finite-element method (FEM) model was built, in which cartilage displacements from the MRI images were used to prescribe the adduction, and the vocal fold deformation was simulated before the eigenmode calculation. The results showed that the frequency comparison between the two sides was consistent with observations from HSV. This alignment between the surgical and computational models supports the future application of these methods for the investigation of treatment for UVFP.


2021 ◽  
Vol 18 (3) ◽  
pp. 428-435
Author(s):  
Vladimir I. SMIRNOV ◽  
◽  
Tatiana A. KNOPOVA ◽  
Sergey S. MAYER ◽  
◽  
...  

Objective: Solving the problem of determining the conditions for the onset and development of unstable fracture, which is extremely important for the development of methods for calculating the limiting states of structural elements, improving the dynamic testing schemes of materials and classifying steels according to their ability to resist fracture. Methods: Analytical methods for assessing the limiting state of structural elements are used. Results: A brief overview of the available test methods for structural steels for dynamic strength and crack resistance is given. The experience accumulated by domestic and foreign practices in testing steels for strength and crack resistance under high-speed loading is analyzed. The disadvantages of the existing methods for assessing the indicators of dynamic strength and resistance to brittle fracture are indicated. Practical importance: It is shown that along with the traditional methods for assessing strength based on safety factors, it is necessary to develop and apply new methods for assessing the limiting state of structural elements, including by the criteria of crack resistance


Author(s):  
Tse guan Tan ◽  
Jason Teo ◽  
On Chin Kim

AbstrakKini, semakin ramai penyelidik telah menunjukkan minat mengkaji permainan Kecerdasan Buatan (KB).Permainan seumpama ini menyediakan tapak uji yang sangat berguna dan baik untuk mengkaji asasdan teknik-teknik KB. Teknik KB, seperti pembelajaran, pencarian dan perencanaan digunakan untukmenghasilkan agen maya yang mampu berfikir dan bertindak sewajarnya dalam persekitaran permainanyang kompleks dan dinamik. Dalam kajian ini, satu set pengawal permainan autonomi untuk pasukan hantudalam permainan Ms. Pac-man yang dicipta dengan menggunakan penghibridan Evolusi PengoptimumanMultiobjektif (EPM) dan ko-evolusi persaingan untuk menyelesaikan masalah pengoptimuman dua objektifiaitu meminimumkan mata dalam permainan dan bilangan neuron tersembunyi di dalam rangkaianneural buatan secara serentak. Arkib Pareto Evolusi Strategi (APES) digunakan, teknik pengoptimumanmultiobjektif ini telah dibuktikan secara saintifik antara yang efektif di dalam pelbagai aplikasi. Secarakeseluruhannya, keputusan eksperimen menunjukkan bahawa teknik pengoptimuman multiobjektif bolehmendapat manfaat daripada aplikasi ko-evolusi persaingan Abstract Recently, researchers have shown an increased interest in game Artificial Intelligence (AI). Gamesprovide a very useful and excellent testbed for fundamental AI research. The AI techniques, such aslearning, searching and planning are applied to generate the virtual creatures that are able to think andact appropriately in the complex and dynamic game environments. In this study, a set of autonomousgame controllers for the ghost team in the Ms. Pac-man game are created by using the hybridizationof Evolutionary Multiobjective Optimization (EMO) and competitive coevolution to solve the bi-objectiveoptimization problem of minimizing the game's score by eating Ms. Pac-man agent and the number ofhidden neurons in neural network simultaneously. The Pareto Archived Evolution Strategy (PAES) is usedthat has been proved to be an effective and efficient multiobjective optimization technique in variousapplications. Overall, the results show that multiobjective optimizer can benefit from the application ofcompetitive coevolutionary


2018 ◽  
Vol 157 ◽  
pp. 02054 ◽  
Author(s):  
Milan Vaško ◽  
Marián Handrik ◽  
Alžbeta Sapietová ◽  
Jana Handriková

The paper presents an analysis of the use of optimization algorithms in parallel solutions and distributed computing systems. The primary goal is to use evolutionary algorithms and their implementation into parallel calculations. Parallelization of computational algorithms is suitable for the following cases - computational models with a large number of design variables or cases where the objective function evaluation is time consuming (FE analysis). As the software platform for application of distributed optimization algorithms is using MATLAB and BOINC software package.


2020 ◽  
Author(s):  
Eszter Szemerédi ◽  
Tibor Tatay

AbstractFor the further development and more efficient operation of the sharing economy, a fast and inexpensive peer-to-peer payment system is an essential element. The aim of this study is to outline a prototype that ensures the automation and decentralization of processes through smart contracts without blockchain technology. The model has been built based on the narrative that a community currency created through smart contracts can promote genuine practices of sharing as opposed to the profit-oriented approach that most of the currently operating sharing economy platforms have. Features of the model, such as ease of use, high-speed transactions without transaction cost are benefits that can provide a more efficient alternative to the traditional or to the cryptocurrency-based centralized sharing economy platforms.


Author(s):  
O. Guseva ◽  
S. Lehominova ◽  
R. Dymenko ◽  
O. Voskoboieva ◽  
O. Romashchenko

Abstract. Taking into account global development trends, integration and globalization processes, encourage the search for and further development of new products, services and management mechanisms. The economic-mathematical model of optimization of parameters of type NBIC-direction of competitive advantages is developed. The model is formed by the criterion of maximizing  the net discounted cashflow. Based on the developed scientific and methodological approach, 4 types of NBIC-direction of competitive advantages of telecommunication enterprises are proposed, which are based on a combination of levels of innovative activity of the enterprise (from low to high) and complementarity of cashflow management (from low to high). As a result, the types of NBIC-direction of competitive advantages of the enterprise are proposed: adaptive-passive, adaptive-active, object-oriented; foresight-progressive. Complementary cashflow management involves a balanced distribution of cashflows by certain NBIC-components, namely: Nano-components (application of Nano-development stop rovide high-speed telecommunications), Bio-components (introduction of artificial intelligence in organizational culture, implementation of self-organization in the enterprise), Info-components (introduction of innovative standards of telecommunication activity, information software in business process management), Cogno-components (cognitive flexibility of top and middle managers, ability of personnel to complementarity, development of knowledge management system at enterprise, introduction of system of continuous training of all employees links). Thus, the combined use of these components provides an increase in cashflows and forms a modern platform for breakthrough competitive development of enterprises. Keywords: management, competitive advantage, cashflow, innovation, complementarity. JEL Classification B26,  D61 Formulas: 14; fig.: 3; tabl.: 2; bibl.: 15.


2010 ◽  
Vol 431-432 ◽  
pp. 425-428
Author(s):  
Kan Zheng ◽  
Wen He Liao ◽  
Xiang Zhang

According to the structural layout and mechanics characteristic of microsatellite, the FEM was established reasonably. Base on the FEM analysis and its characteristics, the structure of microsatellite was optimization designed. In the optimization process, the optimization model was established with the design variables of aluminum panel thickness, core plate thickness and skeleton thickness, and subjected to stiffness, strength, displacement and size constraints. Then, used the sequential quadratic programming method for optimization analysis. The results of the optimization demonstrates that the weight of structure loss significantly, and the whole structure weight of the microsatellite loss 11%.Meanwhile, the iterative times of the optimization process is few, so it is very Meaningful and useful for actual project application.


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