Current Issue : January - March Volume : 2021 Issue Number : 1 Articles : 5 Articles
In model-based system engineering (MBSE), reuse of existing models in the development of a new system can be advantageous.\nAutomatic assignment of existing models to each design task within a design task set has been proven to be feasible. However,\nwhile several studies have discussed the significance of models in MBSE and methodologies for models reuse, solving the model\nreusability problem through a model assignment method has not been discussed. Additionally, a significant challenge in model\nassignment is to address the conflict between the maximization of the model value summations, which are yielded by assigning the\nmodels to a design task set, and the minimization of the execution cycle of the task set. This study (a) proposes a design-taskoriented\nmodel assignment method that establishes a multiobjective model, based on a model assignment integration framework,\nand (b) designs a differential-evolution-combined adaptive nondominated sorting genetic algorithm-II to provide an optimal\ntradeoff between maximizing the total model values and minimizing the execution cycle of the task set. By comparing the\nperformance of the algorithm in resolving the assignment of models to a design task set with those of two conventional algorithms\nin a phased-array radar development project, the algorithmâ??s performance and promotion of system development are verified to\nbe superior.The new method can be applied for developing model scheduling software for MBSE-compliant product development\nprojects to improve using effects of the models and development cycle....
The Bertalanffy-Pütter (BP) five-parameter growth model provides a versatile\nframework for the modeling of growth. Using data from a growth experiment\nin literature about the average size-at-age of 24 species of tropical trees over\nten years in the same area, we identified their best-fit BP-model parameters.\nWhile different species had different best-fit exponent-pairs, there was a\nmodel with a good fit to 21 (87.5%) of the data (â??Good fitâ? means a normalized\nroot-mean-squared-error NRMSE below 2.5%. This threshold was the\n95% quantile of the lognormal distribution that was fitted to the NRMSE values\nfor the best-fit models for the data). In view of the sigmoidal character of\nthis model despite the early stand we discuss whether the setting of the\ngrowth experiment may have impeded growth....
With advancements in computer-aided design, simulation of internal combustion engines has become a vital tool for product\ndevelopment and design innovation. Among the simulation software packages currently available, MATLAB/Simulink is widely\nused for automotive system simulations, but does not contain a comprehensive engine modeling toolbox. To leverage\nMATLAB/Simulinkâ??s capabilities, a Simulink-based 1D flow engine modeling framework has been developed. The framework\nallows engine component blocks to be connected in a physically representative manner in the Simulink environment, reducing\nmodel build time. Each component block, derived from physical laws, interacts with other blocks according to block connection.\nIn this Part 1 of series papers, a comprehensive gas dynamics model is presented and integrated in the engine modeling\nframework based on MATLAB/Simulink. Then, the gas dynamics model is validated with commercial engine simulation\nsoftware by conducting a simple 1D flow simulation....
In recent years, the number of permanent residents in Chengdu, Sichuan\nProvince, China has continued to grow, and the number of private cars keeps\nrising. A series of problems caused by difficult parking and random parking\nin old communities are common. This paper will take the parking problem of\nthe old community in Yingmenkou community, Chengdu, China as an example\nto summarize the current situation and parking problems of the private\ncar parking facilities in these old communities. Based on Chengduâ??s current\nold community parking management policy, parking facility renovation\nand expansion policy, this paper researches and establishes a parking resource\nsharing model suitable for old communities....
Hydroturbines have a very wide range of applications, which are commonly found in wind turbines, water turbines, aero engines,\netc. This paper provided a detailed turbine design and a design method of turbine blade shape.....................................
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