Papers by Keyword: Optimization

Abstract: The use of fly ash in cement and concrete has long been a common practice. However, in the Czech Republic, one of the largest producers of fly ash in the world, there is still a great mistrust of this material. One of the main reasons is variability properties of fly ash. But standard ČSN EN 450-2 defines the possibilities of optimizing the properties of fly ash. This paper is dedicated to optimizing the properties of fly ash, namely sorting and mixing.

Abstract: General principles on probabilistic approach to structural verification with respect to durability are provided in the international standard ISO 13823 which is currently being implemented into the system of Czech standards. The operational use of the new procedures in practice would require specification of probabilistic durability criteria, physical models of material deteriorations, and theoretical models of basic variables. It appears that the probabilistic methods of optimisation may provide valuable background information facilitating determination of appropriate criteria for durability.

Abstract: The estimation of thermal boundary conditions occurring during heat treatment processes is an essential requirement for characterization of heat transfer phenomena. In this work, the performance of five optimization techniques is studied. These models are the Conjugate Gradient Method, the Levenberg-Marquardt Method, the Simplex method, the NSGA II algorithm and a hybrid approach based on the NSGA II and Levenberg-Marquardt Method sequence. The models are used to estimate the heat transfer coefficient in 2D axis symmetrical case during transient heat transfer. The performance of the optimization methods is demonstrated using numerical experiments.

Abstract: Optimal design of an energy efficient building has to meet two confronted demands: to minimize total cost of construction, and to minimize environmental impact and energy consumption, which is usually obtained by the implementation of expensive insulation materials and equipment. Therefore, optimization task cannot be formulated by a single objective function, but requires at least two functions. Consequently, there is no unique, i.e. the best solution, but a number of more or less acceptable ones among which designer chooses a satisfying one considering given demands and limitations. This paper presents methodology for using the Big Bang – Big Crunch algorithm for optimum design of an energy efficient building that would meet two confronted demands – the lowest price and the lowest environmental impact during the 25 years period. Presented study showed that this approach provides several acceptable solutions among which the decision maker can make a choice in accordance with his/her needs and wishes.

Abstract: In this paper, the analysis of the general tendencies of line building of cottage settlement is carried out by houses. The analysis of domestic and foreign development showed that many questions connected with formation of schedules of building of objects of settlement and calculation of parameters of works taking into account restriction on resources at development of local plans of settlement by houses, now finally aren't solved.As practice of construction of settlement shows further improvement of a technique of scheduling of building of settlement by houses has to go on an alternative basis and a choice among them the most effective on economic indicators because of modern computer technologies. The calculation procedure and optimization of options of the line organization of construction of houses because of modern computer technologies is offered.The technique of a technical and economic assessment of optimizing solutions of cottage building is offered. In this paper data on application to the developed technique for scheduling of construction of houses of settlement. The developed techniques can find application when developing projects of the organization of mass building of cottage settlement by houses.

Abstract: The optimization of the camera’s intrinsic and extrinsic parameters is a key step after obtaining the initialized parameters’ state by considering the homography between the board space plane and the image plane in Zhengyou Zhang method. In this paper, we proposed a camera calibration optimization algorithm by adopting genetic algorithm and the simulated annealing algorithm. The experiment results demonstrate that our algorithm can improve the precision of the camera calibration to a certain extent.

Abstract: Sacrificial layer release is the key process step of cavity structure formation of Film Bulk Acoustic Resonator (FBAR), the degree of sacrificial layer release directly determines how good or bad the resonance characteristic of FBAR is. The Constant Diffusion Coefficient (CDC) model numerical iteration of sacrificial layers etching process was simulated with MATLAB, and the etching process was also simulated with Silvaco. According to the simulation results, put forward optimum design of release window. The resonance simulations of FBAR with/without release window have been done by FEA software. The simulation results show that the aperture cavity type FBAR, i.e. the cavity type FBAR with release holes, still has distinct resonant characteristic, but the frequency of impedance zero point and impedance pole of the novel type FBAR are all drifted to higher frequency, and the effective electromechanical coupling coefficient and the quality factor are all reduced.

Abstract: Due to environmental and energy matters, importance of future construction trend-Passive House Design is increasing all over the world. In Europe, already recommended values ​​for passive buildings are included in thermal insulation standards and energy regulation directives. There is a wide range of construction materials nowadays. The key point is using proper techniques by harmonizing correct practice and materials. In this regard, smart optimization set-up approach is necessary in order to achieve the most suitable design which has the lowest CO₂ and SO₂ values and appears as the cheapest option. The sample given in this paper is an example of an exterior wall design for residential passive houses (heat transfer coefficient (U) value through the cross section is 0,108 W/m²K). Connected with the aim of the paper, which is showing an multi-objective optimization method for choosing the best thermal insulation design in the case of that more than one projection, results of given example design in the paper is used. Simultaneously, criteria of total thickness, heat transfer coefficient (U) through the cross section, global warming potential (GWP), acid produce (AP), primary energy content (PEI) non renewable and cost in 2013 per m² are included in “Smart optimization set-up approach diagram”.

Abstract: Optimization of microwave filter structure parameter based on traditional learning methods faces problems like long design cycles, complex calculation and sensitive to initial value, and so on. A hybrid trust region algorithm which combine the improved trust region with the advance and retreat method is introduced to the field of optimization of microwave filter structure parameter for the first time. Comparison between the methods based on the traditional trust region method and the improved trust region method reveals that the algorithm can significantly increase precision and speed of optimization model of the microwave cavity filter parameters.

Abstract: Current trends in micro-architecture are towards larger number of processing elements on a single chip. It is challenging to tap the peak performance of those processors. In order to address this issue, the most promising solution is automatic parallelization. This approach does not require programmer too much effort in the process of parallelizing programs. Polyhedral model is a mathematical framework based on the powerful linear integer programming, which provides an abstraction concept to represent the nested loops computing and dependence of data access using integer points in the polyhedron. We propose an automatic transformation framework based on polyhedral model to optimize nested loop with affine dependences for parallelism and locality.