Frequency: Quarterly E- ISSN: 2277-6273 P- ISSN: Awaited Abstracted/ Indexed in: Ulrich's International Periodical Directory, Google Scholar, SCIRUS, getCITED, Genamics JournalSeek
"Inventi Impact: Modeling & Simulation" is a quarterly journal providing global forum for researchers, scholars and engineers in the fields of modeling and simulation. It publishes high quality refereed research and review papers disseminating latest theoretical results and their practical applications.
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....
A dynamic stiffness element for flexural vibration analysis of delaminated multilayer beams is developed and subsequently used to\r\ninvestigate the natural frequencies and modes of two-layer beam configurations. Using the Euler-Bernoulli bending beam theory,\r\nthe governing differential equations are exploited and representative, frequency-dependent, field variables are chosen based on the\r\nclosed form solution to these equations. The boundary conditions are then imposed to formulate the dynamic stiffness matrix\r\n(DSM), which relates harmonically varying loads to harmonically varying displacements at the beam ends. The bending vibration\r\nof an illustrative example problem, characterized by delamination zone of variable length, is investigated. Two computer codes,\r\nbased on the conventional Finite ElementMethod (FEM) and the analytical solutions reported in the literature, are also developed\r\nand used for comparison. The intact and defective beam natural frequencies and modes obtained from the proposed DSM method\r\nare presented along with the FEM and analytical results and those available in the literature....
The literature has shown that ordinary least squares estimator (OLSE) is not best when the explanatory variables are related, that is,\nwhen multicollinearity is present. This estimator becomes unstable and gives a misleading conclusion. In this study, a modified\nnew two-parameter estimator based on prior information for the vector of parameters is proposed to circumvent the problem of\nmulticollinearity. This new estimator includes the special cases of the ordinary least squares estimator (OLSE), the ridge estimator\n(RRE), the Liu estimator (LE), the modified ridge estimator (MRE), and the modified Liu estimator (MLE). Furthermore, the\nsuperiority of the new estimator over OLSE, RRE, LE, MRE, MLE, and the two-parameter estimator proposed by Ozkale and\nKaciranlar (2007) was obtained by using the mean squared error matrix criterion. In conclusion, a numerical example and a\nsimulation study were conducted to illustrate the theoretical results....
This paper presents a modified grey model GMC(1,...
Developing a suitable nonlinear model is the most challenging problem in the application of nonlinear model based controllers\nto distillation column. Hammerstein model consists of a nonlinear static element described by wavenet based nonlinear function,\nfollowed by a linear dynamic element described by the Output Error(OE) model was used in this study to represent the nonlinear\ndynamics of the distillation column. The model parameters were identified using iterative prediction-error minimization method.\nThe model validation results proved that the Hammerstein model was capable of capturing the nonlinear dynamics of distillation\ncolumn....
A mathematical model was developed to correlate the four heat penetration parameters of 57 Stumbo�s tables (18,513 datasets) in\r\ncanned food: g (the difference between the retort and the coldest point temperatures in the canned food at the end of the heating\r\nprocess), fh/u (the ratio of the heating rate index to the sterilizing value), z (the temperature change required for the thermal\r\ndestruction curve to traverse one log cycle), and Jcc, (the cooling lag factor). The quantities g, z, and Jcc, are input variables for\r\npredicting fh/U, while z, Jcc and fh/U are input variables for predicting the value of g, which is necessary to calculate the heating\r\nprocess time B, at constant retort temperature, using Ball�s formula. The process time calculated using the g value obtained from\r\nthemathematical model closely followed the time calculated fromthe tabulated g values (rootmean square of absolute errors RMS\r\n= 0.567 min, average absolute error = 0.421 min with a standard deviation SD = 0.380 min). Because the mathematical model can\r\nbe used to predict the intermediate values of any combination of inputs, avoiding the storage requirements and the interpolation of\r\n57 Stumbo�s tables, it allows a quick and easy automation of thermal process calculations and to perform these calculations using a\r\nspreadsheet....
Aiming at the shortcomings of traditional broadcast transmitter noise test methods, such as low efficiency, inconvenient data\nstorage, and high requirements for testers, a dynamic online test method for transmitter noise is proposed. The principle of system\ncomposition and test method is given. The transmitter noise is real-time changing. The Voice Active Detection (VAD) noise\nestimation algorithm cannot track the transmitter noise change in real time. This paper proposes a combined noise estimation\nalgorithm for VAD and dynamic estimation. By setting the threshold of the double-threshold VAD detection to be low, it can\naccurately detect the silent segment. The silent segment is used as a noise signal for noise estimation. For the nonsilent segment\ndetected by the VAD, a minimum value search dynamic spectrum estimation algorithm based on the existence probability of the\nspeech (IMCRA) is used for noise estimation. Transmitter noise is measured by calculating the noise figure (NF).The test method\ncollects the input and output data of the transmitter in real time, which has better accuracy and real-time performance, and the\nfeasibility of the method is verified by experimental simulation....
A new sparse Gauss-Hermite cubature rule is designed to avoid dimension explosion caused by the traditional full tensor-product\nbased Gauss-Hermite cubature rule. Although Smolyak�s quadrature rule can successfully generate sparse cubature points for high\ndimensional integral, it has a potential drawback that some cubature points generated by Smolyak�s rule have negative weights,\nwhich may result in instability for the computation. A relative-weight-ratio criterion based sparse Gauss-Hermite rule is presented\nin this paper, in which cubature points are kept symmetric in the input space and corresponding weights are guaranteed to be\npositive.The generation of the newsparse cubature points set is simple and meaningful for practice.The difference between our new\nsparseGauss-Hermite cubature rule and other cubature rules is analysed. Simulation results showthat, comparedwithKalman filter\nwith those types of full tensor-product based Gauss-Hermite rules, our newsparse Gauss-Hermite cubature rule basedKalman filter\ncan lead to a substantially reduced number of cubature points, more stable computation capability, and maintaining the accuracy\nof integration at the same time....
A novel dynamic co-simulation methodology of overall wind turbine systems is presented.\nThis methodology combines aerodynamics, mechanism dynamics, control system dynamics, and\nsubsystems dynamics. Aerodynamics and turbine properties were modeled in FAST (Fatigue,\nAerodynamic, Structures, and Turbulence), and ADAMS (Automatic Dynamic Analysis of Mechanical\nSystems) performed the mechanism dynamics; control system dynamics and subsystem dynamics\nsuch as generator, pitch control system, and yaw control system were modeled and built in\nMATLAB/SIMULINK. Thus, this comprehensive integration of methodology expands both the\nflexibility and controllability of wind turbines. The dynamic variations of blades, rotor dynamic\nresponse, and tower vibration can be performed under different inputs of wind profile, and the\ncontrol strategies can be verified in the different closed loop simulation. Besides, the dynamic\nsimulation results are compared with the measuring results of SCADA (Supervisory Control and\nData Acquisition) of a 2MW wind turbine for ensuring the novel dynamic co-simulation methodology....
Rockburst is a sudden and dynamic failure of rock that can cause serious injury to miners and damage to the underground\nexcavations. Stress path, dynamic disturbance, and support system play important and different roles in the generation processes\nof rockbursts, resulting rockbursts with variety of reasons and failure modes. A test facility that was capable of simulating such\nfactors was developed to study shock behaviour and bursting failure of roadways. The results demonstrate that the modeled\nroadway was in good condition and retained a shock resistance capacity after three drop loads. Until the acceleration amplitude\nincreased to a certain level at the time of the fourth dynamic loading, sudden bursting failure of modeled roadway occurred. Many\nlarge fragments ejected from the upper and middle regions of the roadway, accompanied with loud noise. A deep pit was observed\nafter the bursting failure. The axial of the fan-shaped pit had an angle above the vertical. In addition, shock behaviour of the\nmodeled roadway had been changed by the anchor-net support. Significant differences appeared between the acceleration signals\nmeasured in two roadway sections with and without the anchor-net support. The acceleration magnitude of the supported\nroadway section was strongly reduced by the presence of the anchor-net support. Even when the unsupported roadway section\nunderwent a sudden injection failure, the roadway with anchor-net support was in good condition. This study may eventually lead\nto a methodology for studying the rockbursting resistance capacity of underground roadways....
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