Browsing by Author "Ehelepola, I"

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item: Thesis-Full-text
Acoustic design optimization of close-fitting enclosure using genetic algorithm tool for diesel power generator soundproofing application
(2015-09-16) Ehelepola, I; Chandima, DP
Network providers are faced with significant challenges in delivering backhaul solutions. Given that solutions based on Time Division Multiplexing (TDM), is not providing improved efficiency at a reasonable cost. Thus the need for new backhaul solutions is becoming significant. With the full-IP evolution, all the mobile networks are migrated to full-IP, thus capabilities inherent to traditional TDM needs to be developed in these IP networks. Real-time applications have relatively tight timing requirements concerning delay and delay variations. Therefore, need efficient timing solution for those real-time applications. Synchronization is important aspect in networks and it is more critical in mobile networks. Loss of synchronization in mobile networks leads to call drops, mobile broadband data speed degrades and packet losses. Network equipment should be synchronized in frequency, time and time of day. To achieve the packet network based synchronization new strategies should be adopted. Else, traditional synchronization techniques is to be continued to synchronize networks. Specialized synchronization networks can deliver better and accurate performances, but that is with a higher cost. There are new technologies introduced to the industry for synchronization. Before migrating in to new technologies, analyzing these techniques against the service delivery requirement is a prerequisite. There is information available and accessible for the operators, in the areas related to developments of technical standardization proceedings, but there is clear lack of resources and information for practical implementations. There are gaps to be addressed while migration mobile networks into packet switching networks. Migration from circuit switching network to packet switching networks will break the synchronization chain. Most importantly, delivering the synchronization across the borders is required to interwork communication systems. Packet networks are asynchronous in nature therefore integrating time aware applications with packet network require correct timing at the interfaces to provide acceptable performance. Hence, special consideration and design is required in All-IP networks. Cost plays a major role in the adaptation of modern technologies to existing telecommunication networks. Hence backhauling need to be a highly cost effective. At present, the IP networks have proven to be the most cost effective and thus migrating mobile network to a full-IP based network with synchronization capability provides additional cost benefit for the network operators. In this research, technical standards and available synchronization methods are extensively evaluated. Moreover, network requirements, possibilities and limitations are also extensively analyzed. Logical behaviors are compared and analyzed for standardized synchronization techniques. Based on these analyses, implementation guidelines have been developed. The guidelines have been prepared within the overall technical framework published by ITU-T standards and it is hoped that they will be helpful for the mobile operators who wish to migrate from existing network to future proof capacity agile packet switching network.
item: Conference-Full-text
Design optimization of a power generator soundproofing enclosure
(Institute of Electrical and Electronics Engineers, Inc., 2018-09) De Zoysa, ADN; Iroshan, KA; Premaratne, UK; Ehelepola, I; Samarasinghe, R; Abeygunawardana, S
It is a vital requirement to have passive noise control enclosure in order to depress air borne noise of reciprocating engine type power generators. The design of these enclosures needs to be optimized in terms of the sound pressure level and the designing cost. We have used the existing acoustic equations to obtain the optimization based on the objective functions derived for the sound pressure level and enclosure design cost. Metaheuristic optimization algorithms such as genetic algorithms and particle swarm algorithm are capable of solving these optimization problems which have constraints for different parameters. The results obtained for a real world design problem confirms that particle swarm optimization provides better results than genetic algorithm in terms of optimality of the solutions and also the computational efficiency. Furthermore, it was observed that there is a significant linear relationship (R-Squared = 99.3%, p-value < 0.001) between the minimum enclosure design cost and the sound pressure level of the enclosure (SPLE) for the preferred range for SPLE values (65 to 70). The minimum possible enclosure design cost increases linearly with decreasing SPLE value. Therefore, the least possible SPLE value depends on the available financial resources.
item: Conference-Abstract
Design optimization of power generator soundproofing enclosure using genetic algorithm tool
Ehelepola, I; Chandima, DP
This paper introduces a numerical method for optimally designing a passive noise control enclosure for depressing air borne noise of reciprocating engine type power generators. Sound pressure level of soundproofed power generator has been modeled using sound pressure level of unenclosed power generator and insertion loss of passive enclosure. In this context, mathematically developed acoustic equation optimized for the design variables of dimensions, panel material properties and thickness of enclosures under constrains of sound pressure level, cost, weight, and size of enclosures. Genetic Algorithm tool was used for optimization and it has developed in MATLAB software. The developed optimized model has validated by designing and fabricating a passive enclosure for a diesel power generator with a capacity of 22kVA. Eventually the developed design procedure is giving a simple and fast design tool with Graphical User Interface run in MATLAB to provide locally optimized enclosure design parameter which can be used for conceptualize the enclosure design.