scholarly journals Accelerated vs. real time modeling for shelf life: an example with fortified blended foods

2014 ◽  
Vol 17 (3) ◽  
pp. 83-91
Author(s):  
Uyen Thuy Xuan Phan ◽  
Chambers, Edgar IV ◽  
Padmanabhan, Natarajan ◽  
Alavi, Sajid
Keyword(s):  
Relative Humidity ◽  
Shelf Life ◽  
Real Time ◽  
Life Testing ◽  
Time Model ◽  
The Real ◽  
Life Study ◽  
Time Modeling ◽  
Life Model ◽  
Deterioration Process

Shelf life can be simply defined as the duration of that the food remains acceptable for consumption. Determining shelf life of a product, thus, has become essential in quality control because consumer’s demands for safe and high quality products have increased. Accelerated shelf life testing (ASLT), which subjects the food to environments that are more severe than normal to speed up the deterioration process, has long been used in shelf life studies because it can help make decisions more quickly by minimizing time and it minimizes costs. The criterion used to determine shelf life can be the changes in either physical, chemical, biological or sensory characteristics. This study used sensory descriptive properties as the primary criteria to investigate the validity of using Accelerated Shelf Life Testing (ASLT) to determine shelf life of four extruded fortified blended foods (FBFs) compared to a real time model. The real-time environment was set at 300C and 65% relative humidity, based on the weather in Tanzania, the expected location of product use. The ASLT environment was at 500C and 70% relative humidity based on a Q factor of 2, which was equivalent to a one-week ASLT equals onemonth real time. The samples were evaluated for aroma and flavor by a highly trained descriptive panel for 3 time points in each shelf life model. Among the eighteen attributes tested, rancid and painty were the main sensory criteria to determine the shelf life of the products. The ASLT shelf life predictive model was consistent with the real time shelf life for three of the samples. However, it failed to predict the real time shelf life of the fourth similar sample. This affirms the essential use of real time modeling in shelf life study for a new product, even when an accelerated model has been developed for other similar products in the same category. ASLT testing can still be used, but only for early guidance or after validation.

Research on the Real-Time Model of Aero-Engine Actuator

2014 ◽  
Vol 568-570 ◽  
pp. 1036-1040 ◽  
Author(s):  
Hua Cong Li ◽  
Hong An Zhang ◽  
Xiao Bao Han ◽  
Jiang Feng Fu
Keyword(s):  
Real Time ◽  
Dynamic Simulation ◽  
Computational Efficiency ◽  
Flow Coefficient ◽  
Time Model ◽  
The Real ◽  
Time Performance ◽  
Time Modeling ◽  
Aero Engine ◽  
Step Algorithm

Since the solving process of hydraulic dynamic simulation is complex and computational ineffectiveness,the aero-engine actuators real-time modeling is presented in this paper. Combined with the precise model, the convergence of the model and flow coefficient is analyzed. The real-time model operates a number of solving processes in one 20ms simulation cycle and the convergence of fix-step algorithm is guaranteed by adjusting the relevant parameters. The simulation shows that the real-time model can improve the computational efficiency with satisfactory real-time performance and precision.

Micro Gas Turbine Real-Time Modeling: Test Rig Verification

2009 ◽  
Author(s):  
Francesco Ghigliazza ◽  
Alberto Traverso ◽  
Matteo Pascenti ◽  
Aristide F. Massardo
Keyword(s):  
Fuel Cell ◽  
Real Time ◽  
Gas Turbine ◽  
Simulation Models ◽  
Time Dependent ◽  
Test Rig ◽  
Time Model ◽  
The Real ◽  
Micro Gas Turbine ◽  
Time Modeling

This paper reports on the latest application of a generic time-dependent real-time simulation tool, originally developed for fuel cell gas turbine hybrid systems, and now applied to an actual micro gas turbine test rig. Real-time modeling is a recognized approach for monitoring advanced systems and improving control capabilities: applications of real-time models are commonly used in the automotive and aircraft fields. The overall objective is improving of calculation time in existing time-dependent simulation models, while retaining acceptable accuracy of results. The real-time modeling approach already applied to fuel cell gas turbine systems has here been validated against the experimental data from the micro gas turbine Turbec T100 test rig in Savona, Italy. The real-time model of the microturbine recuperator has been newly developed to fit such an application. Two representative transient operations have been selected for verification: the heating and cooling phases of the connected volume. The results already show an acceptable agreement with measurements, and they have contributed to a better insight into performance prediction for the entire plant.

scholarly journals Real-Time Human in the Loop MBS Simulation in the Fraunhofer Robot-Based Driving Simulator

2014 ◽  
Vol 61 (2) ◽  
pp. 270-285 ◽  
Author(s):  
Michael Kleer ◽  
Andrey Gizatullin ◽  
Klaus Dreßler ◽  
Steffen Müller
Keyword(s):  
Real Time ◽  
Driving Simulator ◽  
Practical Significance ◽  
Time Model ◽  
Test Drive ◽  
The Real ◽  
Transport Delay ◽  
Human In The Loop ◽  
Acceleration Signal ◽  
Time Calculation

Abstract The paper encompasses the overview of hardware architecture and the systems characteristics of the Fraunhofer driving simulator. First, the requirements of the real-time model and the real-time calculation hardware are defined and discussed in detail. Aspects like transport delay and the parallel computation of complex real-time models are presented. In addition, the interfacing of the models with the simulator system is shown. Two simulator driving tests, including a fully interactive rough terrain driving with a wheeled excavator and a test drive with a passenger car, are set to demonstrate system characteristics. Furthermore, the simulator characteristics of practical significance, such as simulator response time delay, simulator acceleration signal bandwidth obtained from artificial excitation and from the simulator driving test, will be presented and discussed.

Real-Time Model Method Research in Ship Pipeline System Leakage Detecting

2011 ◽  
Vol 105-107 ◽  
pp. 685-688 ◽  
Author(s):  
Hong Hao Yin ◽  
Hui Chen ◽  
Zhong Bo Peng
Keyword(s):  
Experimental Data ◽  
Pressure Gradient ◽  
Real Time ◽  
Pipeline System ◽  
Safe Operation ◽  
Time Model ◽  
Positioning Accuracy ◽  
The Real ◽  
Model Method ◽  
The Difference

Leakage of ship pipeline system has become a great hidden danger, which affects safe operation of ship and causes environmental pollution. In order to isolate leaking pipeline safely in emergency conditions, Real-time monitoring of ship pipeline system leakage is very important. In this paper, the real-time models of ship isothermal and thermal pipeline were established with a set of equations which is running synchronized with the actual execution pipeline, and the real-time model method was used to monitor ship pipeline system leakage. If the difference between measured values and calculated values is greater than a certain range, pipeline leakage is identified. The location of leakage is calculated based on pressure gradient. Only pressure, flow and temperature of the first and second end of the pipeline were needed, can this method achieve leakage detecting and locating. According to the analysis and verification from the experimental data, this method has high leakage resolution and positioning accuracy.

Real-Time Modeling to Enable Hardware-in-the-Loop Simulation of Plug-In Electric Vehicle-Grid Interaction

2017 ◽  
Author(s):  
Chong Cao ◽  
Luting Wang ◽  
Bo Chen ◽  
Jason Harper ◽  
Theodore Bohn ◽  
...  
Keyword(s):  
Power System ◽  
Real Time ◽  
Electric Vehicle ◽  
Power Management ◽  
Hardware In The Loop ◽  
The Real ◽  
System Models ◽  
Management Algorithm ◽  
Time Modeling ◽  
Building Load

Real-Time simulation and Hardware-in-the-Loop (HIL) testing are increasingly adopted by industry for the development and validation of complex systems. This paper presents the real-time modeling and power management of a Vehicle-Grid Integration (VGI) system. The VGI system consists of six AC level 2 Plug-in Electric Vehicle (PEV) charging stations, a Photovoltaics (PV) farm, a commercial building load, and a switch connecting to 240V single phase power grid. PEV charging activities follow the SAE J1772 standard. An energy management algorithm is designed for the VGI system to coordinate the PEV charging with the building load and PV renewable generation. The coordination maintains the power consumption of the VGI system below utility’s demand charge pricing threshold. A real-time power system simulator, Opal-RT, is used in this study. The OPAL-RT system allows users to build detailed power system models using Matlab Simulink/SimPowerSystems and RT-LAB library, and run the models in real-time. The model-based approach enables the integration of power system models seamlessly with the power management algorithm and power electronics-level controllers. The simulation results show that the VGI model emulates the real system well and the coordinated PEV charging helps to balance the power generation and consumption of the VGI system to meet power management requirement.

scholarly journals ABOUT DEVELOPMENT OF SIMULATION FROM ANTIQUITY TO OUR DAYS

2018 ◽  
Vol 13 (1) ◽  
pp. 119-125
Author(s):  
Михаил Волхонов ◽  
Mihail Volhonov ◽  
Игорь Зимин ◽  
Igor' Zimin ◽  
Иван Максимов ◽  
...  
Keyword(s):  
Real Time ◽  
Human Activity ◽  
Functional Information ◽  
Sources Of Information ◽  
Time Model ◽  
The Real ◽  
Scientific Experiment ◽  
Production Experiment ◽  
Degree Of Certainty ◽  
Mental Modeling

In the article, based on the analysis of available sources of information, information on various types of modeling is systematized and presented, an improved classification is proposed according to which one can distinguish: full, incomplete and approximate (in completeness); stochastic and deterministic (by degree of certainty); discrete, discrete-continuous, continuous (by intermittence); static and dynamic (by the change in time); constructive and descriptive (by the presence of controlled variables); functional, information, behavioral (depending on the aspect of modeling); educational, experimental, scientific and technical, game and imitation (in the field of modeling); mental and real (in the form of implementation); the real, depending on the method of implementation, is divided into the natural (scientific experiment, complex tests, production experiment) and physical (in real time, model time and without time); depending on whether the computer is used for mental modeling is divided into computer and non-computer. By the way of realization, the mental is divided into visual (hypothetical, analog and mocked), symbolic (linguistic and sign) and mathematical (situational, cybernetic, structural, analytical, algorithmic and combined). Also, the mathematical, depending on the properties reflected, is divided into geometric, probabilistic and topological. The article presents historical facts related to the stages of the development of modeling. Causes and main directions of development of modeling and direction of human activity are indicated, in which modeling currently performs one of the main roles.

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