ABSTRACT
The paper provides a short history of the operations research (OR) in Slovenia. Some major events and achievements are mentioned and briefly discussed. The period starts in the year 1964, with the first symposium on OR in Slovenia. In the following decades, there were several important milestones: (1) the start of master's and Ph.D. studies in OR in 1974, (2) the establishment of SSI-SSOR in 1992 (SSI-SSOR stands for the Slovenian Section for Operational Research within the Slovenian Society of Informatics), and (3) the start of a series of symposia in operations research in 1993. All these activities resulted in an extensive list of publications, projects, and monographs and international connections, proving that OR is still a vibrant field, which facilitates knowledge transfer from pure research to business applications.
ABSTRACT
The rapid worldwide evolution of LEDs as light sources has brought new challenges, which means that new methods are needed and new algorithms have to be developed. Since the majority of LED luminaries are of the multi-source type, established methods for the design of light engines cannot be used in the design of LED light engines. This is because in the latter case what is involved is not just the design of a good reflector or projector lens, but the design of several lenses which have to work together in order to achieve satisfactory results. Since lenses can also be bought off the shelf from several manufacturers, it should be possible to combine together different off the shelf lenses in order to design a good light engine. However, with so many different lenses to choose from, it is almost impossible to find an optimal combination by hand, which means that some optimization algorithms need to be applied. In order for them to work properly, it is first necessary to describe the input data (i.e. spatial light distribution) in a functional form using as few as possible parameters. In this paper the focus is on the approximation of the input data, and the implementation of the well-known mathematical procedure for the separation of linear and nonlinear parameters, which can provide a substantial increase in performance.
Subject(s)
Light , Semiconductors , Algorithms , Computer Graphics , Equipment Design , Nonlinear DynamicsABSTRACT
The analytical model [Moreno and Sun, Opt. Express 16, 1808-1819 (2008)] is applied to LED with attached secondary optics. It is shown that a slightly modified model using only three cosine power functions can be used for the cases with symmetric radiation pattern and that good fitting on realistic examples can be achieved with several standard optimization algorithms including local search heuristics and genetic algorithm.
