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Number of results: 9
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Abstract

This paper presents a model of scheduling of multi unit construction project based on an NP-hard permutation flow shop problem, in which the considered criterion is the sum of the costs of the works' execution of the project considering the time of the project as a constraint. It is also assumed that each job in the units constituting the project may be realized in up to three different ways with specific time and cost of execution. The optimization task relies on solving the problem with two different decision variables: the order of execution of units (permutation) and a set of ways to carry out the works in units. The task presented in the paper is performed with the use of a created algorithm which searches the space of solutions in which metaheuristic simulated annealing algorithm is used. The paper presents a calculation example showing the applicability of the model in the optimization of sub-contractors' work in the construction project.

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Authors and Affiliations

M. Podolski
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Abstract

The paper is an exploration of the optimal design parameters of a space-constrained electromagnetic vibration-based generator. An electromagnetic energy harvester is composed of a coiled polyoxymethylen circular shell, a cylindrical NdFeB magnet, and a pair of helical springs. The magnet is vertically confined between the helical springs that serve as a vibrator. The electrical power connected to the coil is actuated when the energy harvester is vibrated by an external force causing the vibrator to periodically move through the coil. The primary factors of the electrical power generated from the energy harvester include a magnet, a spring, a coil, an excited frequency, an excited amplitude, and a design space. In order to obtain maximal electrical power during the excitation period, it is necessary to set the system’s natural frequency equal to the external forcing frequency. There are ten design factors of the energy harvester including the magnet diameter (Dm), the magnet height (Hm), the system damping ratio (ζsys), the spring diameter (Ds), the diameter of the spring wire (ds), the spring length (ℓs), the pitch of the spring (ps), the spring’s number of revolutions (Ns), the coil diameter (Dc), the diameter of the coil wire (dc), and the coil’s number of revolutions (Nc). Because of the mutual effects of the above factors, searching for the appropriate design parameters within a constrained space is complicated. Concerning their geometric allocation, the above ten design parameters are reduced to four (Dm, Hm, ζsys, and Nc). In order to search for optimal electrical power, the objective function of the electrical power is maximized by adjusting the four design parameters (Dm, Hm, ζsys, and Nc) via the simulated annealing method. Consequently, the optimal design parameters of Dm, Hm, ζsys, and Nc that produce maximum electrical power for an electromagnetic energy harvester are found.
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Authors and Affiliations

Min-Chie Chiu
Ying-Chun Chang
Long-Jyi Yeh
Chiu-Hung Chung
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Abstract

In this paper, a four-pole system matrix for evaluating acoustic performance (STL) is derived using a decoupled numerical method. During the optimization process, a simulated annealing (SA) method, which is a robust scheme utilized to search for the global optimum by imitating a physical annealing process, is used. Prior to dealing with a broadband noise, to recheck the SA method’s reliability, the STL’s maximization relative to a one-tone noise (400Hz) is performed. To assure the accuracy of muffler’s mathematical model, a theoretical analysis of one-diffuser muffler is also confirmed by an experimental data. Subsequently, the optimal results of three kinds of mufflers (muffler A: one diffuser; muffler B: two diffusers; muffler C: three diffusers) have also been compared. Results reveal that the acoustical performance of mufflers will increase when the number of diffusers installed at the muffler inlet increases
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Bibliography

1. Bie D.A., Hansen C.H. (1988), Engineering Noise Control: Theory and Practice, Unwin Hyman, London.
2. Chang Y.C., Yeh L.J., Chiu M.C. (2004), Numerical studies on constrained venting system with side inlet/outlet mufflers by GA optimization, Acta Acustica united with Acustica, 90(6): 1159–1169.
3. Chang Y.C., Yeh L.J., Chiu M.C. (2005a), Shape optimization on double-chamber mufflers using genetic algorithm, Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science, 219(1): 31–42, doi: 10.1243/095440605X8351.
4. Chang Y.C., Yeh L.J., Chiu M.C., Lai G.J. (2005b), Shape optimization on constrained singlelayer sound absorber by using GA method and mathematical gradient methods, Journal of Sound and Vibration, 1286(4–5): 941–961, doi: 10.1016/j.jsv.2004.10.039.
5. Chiu M.C. (2009a), Optimization of equipment allocation and sound-barriers shape in a multi-noise plant by using simulated annealing, Noise & Vibration Worldwide, 40(7): 23–35, doi: 10.1260/095745609788921857.
6. Chiu M.C. (2009b), Simulated annealing optimization on multi-chamber mufflers hybridized with perforated plug-inlet under space constraints, Archives of Acoustics, 34(3): 305–343.
7. Chiu M.C. (2010a), Numerical optimization of a threechamber muffler hybridized with a side inlet and a perforated tube by SA method, Journal of Marine Science and Technology, 18(4): 484–495, doi: 10.51400/2709-6998.1897.
8. Chiu M.C. (2010b), Optimal design of multi-chamber mufflers hybridized with perforated intruding inlets and resonated tube using simulated annealing, Journal of Vibration and Acoustics, 132(5): Article ID 054503, doi: 10.1115/1.4001514.
9. Chiu M.C. (2012), Noise elimination of a multi-tone broadband noise with hybrid Helmholtz mufflers using a simulated annealing method, Archives of Acoustics, 37(4): 489–498, doi: 10.2478/v10168-012-0061-0.
10. Chiu M.C. (2013), Numerical assessment for a broadband and tuned noise using hybrid mufflers and a simulated annealing method, Journal of Sound and Vibration, 332(12): 2923–2940, doi: 10.1016/j.jsv.2012.12.039.
11. Chiu M.C. (2014a), Acoustical treatment of multi-tone broadband noise with hybrid side-branched mufflers using a simulated annealing method, Journal of Low Frequency Noise Vibration and Active Control, 33(1): 79–112, doi: 10.1260/0263-0923.33.1.79.
12. Chiu M.C. (2014b), Optimal design on one-layer closefitting acoustical hoods using a simulated annealing method, Journal of Marine Science and Technology, 22(2): 211–217, doi: 10.6119/JMST-013-0503-1.
13. Chiu M.C., Chang Y.C. (2014), An assessment of high-order-mode analysis and shape optimization of expansion chamber mufflers, Archives of Acoustics, 39(4): 489–499, doi: 10.2478/aoa-2014-0053.
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Authors and Affiliations

Min-Chie Chiu
1
Ho-Chih Cheng
2

  1. Department of Mechanical and Materials Engineering, Tatung University, Taiwan, R.O.C.
  2. Department of Intelligent Automation Engineering, Chung Chou University of Science and Technology, Taiwan, R.O.C.
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Abstract

In the calculations presented in the article, an artificial immune system (AIS) was used to plan the routes of the fleet of delivery vehicles supplying food products to customers waiting for the delivery within a specified, short time, in such a manner so as to avoid delays and minimize the number of delivery vehicles. This type of task is classified as an open vehicle routing problem with time windows (OVRPWT). It comes down to the task of a traveling salesman, which belongs to NP-hard problems. The use of the AIS to solve this problem proved effective. The paper compares the results of AIS with two other varieties of artificial intelligence: genetic algorithms (GA) and simulated annealing (SA). The presented methods are controlled by sets of parameters, which were adjusted using the Taguchi method. Finally, the results were compared, which allowed for the evaluation of all these methods. The results obtained using AIS proved to be the best.

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Authors and Affiliations

B. Mrówczyńska
A. Król
P. Czech
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Abstract

This paper presents methods for optimal test frequencies search with the use of heuristic approaches. It includes a short summary of the analogue circuits fault diagnosis and brief introductions to the soft computing techniques like evolutionary computation and the fuzzy set theory. The reduction of both, test time and signal complexity are the main goals of developed methods. At the before test stage, a heuristic engine is applied for the principal frequency search. The methods produce a frequency set which can be used in the SBT diagnosis procedure. At the after test stage, only a few frequencies can be assembled instead of full amplitude response characteristic. There are ambiguity sets provided to avoid a fault tolerance masking effect.

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Authors and Affiliations

P. Jantos
D. Grzechca
T. Golonek
J. Rutkowski
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Abstract

Improving production processes includes not only activities concerning manufacturing itself, but also all the activities that are necessary to achieve the main objectives. One such activity is transport, which, although a source of waste in terms of adding value to the product, is essential to the realization of the production process. Over the years, many methods have been developed to help manage supply and transport in such a way as to reduce it to the necessary minimum. In the paper, the problem of delivering components to a production area using trains and appropriately laid-out carriages was described. It is a milk run stop locations problem (MRSLP), whose proposed solution is based on the use of heuristic algorithms. Intelligent solutions are getting more and more popular in the industry because of the possible advantages they offer, especially those that include the possibility of finding an optimum local solution in a relatively short time and the prevention of human errors. In this paper, the applicability of three algorithms – tabu search, genetic algorithm, and simulated annealing – was explored.
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Authors and Affiliations

Joanna Kochańska
1
Anna Burduk
1
ORCID: ORCID
Dagmara Łapczyńska
1
Kamil Musiał
1

  1. Faculty of Mechanical Engineering, Wroclaw University of Science and Technology, 50-370 Wroclaw, Poland
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Abstract

Groundwater contamination due to leakage of gasoline is one of the several causes which affect the groundwater environment by polluting it. In the past few years, In-situ bioremediation has attracted researchers because of its ability to remediate the contaminant at its site with low cost of remediation. This paper proposed the use of a new hybrid algorithm to optimize a multi-objective function which includes the cost of remediation as the first objective and residual contaminant at the end of the remediation period as the second objective. The hybrid algorithm was formed by combining the methods of Differential Evolution, Genetic Algorithms and Simulated Annealing. Support Vector Machines (SVM) was used as a virtual simulator for biodegradation of contaminants in the groundwater flow. The results obtained from the hybrid algorithm were compared with Differential Evolution (DE), Non Dominated Sorting Genetic Algorithm (NSGA II) and Simulated Annealing (SA). It was found that the proposed hybrid algorithm was capable of providing the best solution. Fuzzy logic was used to find the best compromising solution and finally a pumping rate strategy for groundwater remediation was presented for the best compromising solution. The results show that the cost incurred for the best compromising solution is intermediate between the highest and lowest cost incurred for other non-dominated solutions.

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Authors and Affiliations

Deepak Kumar
Sudheer Ch
Shashi Mathur
Jan Adamowski

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