scholarly journals Design Improvement for Complex Systems with Uncertainty

Mathematics ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 1173
Author(s):  
Yue Chen ◽  
Jian Shi ◽  
Xiao-Jian Yi
Keyword(s):  
Complex Systems ◽  
System Performance ◽  
Black Box ◽  
Design Parameters ◽  
Engineering System ◽  
Engineering Knowledge ◽  
Design Improvement ◽  
Design Goal ◽  
Maximum Solution ◽  
High Possibility

The uncertainty of the engineering system increases with its complexity, therefore, the tolerance to the uncertainty becomes important. Even under large variations of design parameters, the system performance should achieve the design goal in the design phase. Therefore, engineers are interested in how to turn a bad design into a good one with the least effort in the presence of uncertainty. To improve a bad design, we classify design parameters into key parameters and non-key parameters based on engineering knowledge, and then seek the maximum solution hyper-box which already includes non-key parameters of this bad design. The solution hyper-box on which all design points are good, that is, they achieve the design goal, provides target intervals for each parameter. The bad design can be turned into a good one by only moving its key parameters into their target intervals. In this paper, the PSO-Divide-Best method is proposed to seek the maximum solution hyper-box which is in compliance with the constraints. This proposed approach has a considerably high possibility to find the globally maximum solution hyper-box that satisfies the constraints and can be used in complex systems with black-box performance functions. Finally, case studies show that the proposed approach outperforms the EPCP and IA-CES methods in the literature.

scholarly journals A Globally Optimal Robust Design Method for Complex Systems

Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-25
Author(s):  
Yue Chen ◽  
Jian Shi ◽  
Xiao-jian Yi
Keyword(s):  
Complex Systems ◽  
Design Parameter ◽  
Design Method ◽  
Solution Space ◽  
Maximum Size ◽  
Design Criterion ◽  
Design Parameters ◽  
Engineering System ◽  
Output Performance ◽  
Maximum Solution

The uncertainty of the engineering system increases with the growing complexity of the engineering system; therefore, the tolerance to the uncertainty is essential. In the design phase, the output performance should reach the design criterion, even under large variations of design parameters. The tolerance to design parameter variations may be measured by the size of a solution space in which the output performance is guaranteed to deliver the required performance. In order to decouple dimensions, a maximum solution hyperbox, expressed by intervals with respect to each design parameter, is sought. The proposed approach combines the metaheuristic algorithm with the DIRECT algorithm where the former is used to seek the maximum size of hyperbox, and the latter is used as a checking technique that guarantees the obtained hyperbox is indeed a solution hyperbox. There are three advantages of the proposed approach. First, it is a global search and has a considerable high possibility to produce the globally maximum solution hyperbox. Second, it can be used for both analytically known and black-box performance functions. Third, it guarantees that any point selected within the obtained hyperbox satisfies the performance criterion as long as the performance function is continuous. Furthermore, the proposed approach is illustrated by numerical examples and real examples of complex systems. Results show that the proposed approach outperforms the GHZ and CES-IA methods in the literature.

scholarly journals Community Design Parameters and the Performance of Residential Cogeneration Systems

2007 ◽  
Vol 4 (2) ◽  
Author(s):  
Hazem Rashed-Ali
Keyword(s):  
System Performance ◽  
Design Parameters ◽  
Base Line ◽  
Line Model ◽  
Residential Communities ◽  
Mixed Use ◽  
Study Results ◽  
Cogeneration System ◽  
Design Characteristics ◽  
The Impact

The integration of cogeneration systems in residential and mixed-use communities has the potential of reducing their energy demand and harmful emissions and can thus play asignificant role in increasing their environmental sustainability. This study investigated the impact of selected planning and architectural design parameters on the environmental and economic performances of centralized cogeneration systems integrated into residential communities in U.S.cold climates. Parameters investigated include: 1) density, 2) use mix, 3) street configuration, 4) housing typology, 5) envelope and building systems’ efficiencies, and 6) passive solar energyutilization. The study integrated several simulation tools into a procedure to assess the impact of each design parameter on the cogeneration system performance. This assessment procedure included: developing a base-line model representing typical design characteristics of U.S. residential communities; assessing the cogeneration system’s performance within this model using three performance indicators: percentage of reduction in primary energy use, percentage of reduction in CO2 emissions; and internal rate of return; assessing the impact of each parameter on the system performance through developing 46 design variations of the base-line model representing potential changes in each parameter and calculating the three indicators for each variation; and finally, using a multi-attribute decision analysis methodology to evaluate the relative impact of each parameter on the cogeneration system performance. The study results show that planning parameters had a higher impact on the cogeneration system performance than architectural ones. Also, a significant correlation was found between design characteristics identified as favorable for the cogeneration system performance and those of sustainable residential communities. These include high densities, high use mix, interconnected street networks, and mixing of housing typologies. This indicates a higher potential for integrating cogeneration systems in sustainable communities.Keywords: cogeneration; residential & mixed use communities; energy efficiency; district heating

Design Improvement by Sensitivity Analysis (DISA) Under Interval Uncertainty Using Multi-Objective Optimization

2009 ◽  
Author(s):  
J. Hamel ◽  
M. Li ◽  
S. Azarm
Keyword(s):  
Sensitivity Analysis ◽  
Interval Uncertainty ◽  
Minimal Amount ◽  
Engineering System ◽  
Objective Functions ◽  
Multi Objective Optimization ◽  
New Approach ◽  
Design Improvement ◽  
Multi Objective ◽  
System A

Uncertainty in the input parameters to an engineering system may not only degrade the system’s performance, but may also cause failure or infeasibility. This paper presents a new sensitivity analysis based approach called Design Improvement by Sensitivity Analysis (DISA). DISA analyzes the interval parameter uncertainty of a system and, using multi-objective optimization, determines an optimal combination of design improvements required to enhance performance and ensure feasibility. This is accomplished by providing a designer with options for both uncertainty reduction and, more importantly, slight design adjustments. The approach can provide improvements to a design of interest that will ensure a minimal amount of variation in the objective functions of the system while also ensuring the engineering feasibility of the system. A two stage sequential framework is used in order to effectively employ metamodeling techniques to approximate the analysis function of an engineering system and greatly increase the computational efficiency of the approach. This new approach has been applied to two engineering examples of varying difficulty to demonstrate its applicability and effectiveness.

scholarly journals A Black-Box method for parametric model order reduction based on matrix interpolation with application to simulation and control

2016 ◽  
Vol 64 (9) ◽  
Author(s):  
Matthias Geuß
Keyword(s):  
Model Order Reduction ◽  
Order Reduction ◽  
Black Box ◽  
Design Parameters ◽  
Dimensional Parameter ◽  
Model Order ◽  
Parametric Model Order Reduction ◽  
Box Method ◽  
Matrix Interpolation ◽  
And Control

AbstractThis thesis deals with model order reduction of parameter-dependent systems based on interpolation of locally reduced system matrices. A Black-Box method is proposed that automatically determines the optimal design parameters and delivers a reduced system with desired accuracy. In addition, the method is extended to stability preservation and interpolation for high-dimensional parameter spaces.

Swing Phase Simulation and Design of Above Knee Prostheses

1986 ◽  
Vol 108 (1) ◽  
pp. 65-72 ◽  
Author(s):  
C.-S. Tsai ◽  
J. M. Mansour
Keyword(s):  
System Performance ◽  
Current Practice ◽  
Walking Speed ◽  
Swing Phase ◽  
Design Parameters ◽  
Light Weight ◽  
Simple Design ◽  
Knee Prostheses ◽  
Constant Friction ◽  
Overall Performance

A detailed dynamic model of the stump-prosthesis system for an above knee amputee was developed. The model was used to examine the influence of controls and design parameters on the limb system performance during the swing phase of gait. The model duplicated the clinically known fact that hydraulic knee controllers allow the amputee to change walking speed while mechanical knee controllers limit the amputee to a single walking speed. Contrary to current practice, the simulations suggest that light weight prosthesis designs do not perform as well as heavier designs. A simple design based on a constant friction knee is shown to yield good overall performance.

Modeling Strategic Behavior in Human-Automation Interaction: Why an "Aid" Can (and Should) Go Unused

1993 ◽  
Vol 35 (2) ◽  
pp. 221-242 ◽  
Author(s):  
Alex Kirlik
Keyword(s):  
Sensitivity Analysis ◽  
System Performance ◽  
Strategic Behavior ◽  
Task Demands ◽  
Design Parameters ◽  
Task Context ◽  
Effective Operator ◽  
Effective Strategies ◽  
Potential Benefits ◽  
Intelligent Assistant

Task-offload aids (e.g., an autopilot, an "intelligent" assistant) can be selectively engaged by the human operator to dynamically delegate tasks to automation. Introducing such aids eliminates some task demands but creates new ones associated with programming, engaging, and disengaging the aiding device via an interface. The burdens associated with managing automation can sometimes outweigh the potential benefits of automation to improved system performance. Aid design parameters and features of the overall multitask context combine to determine whether or not a task-offload aid will effectively support the operator. A modeling and sensitivity analysis approach is presented that identifies effective strategies for human-automation interaction as a function of three task-context parameters and three aid design parameters. The analysis and modeling approaches provide resources for predicting how a well-adapted operator will use a given task-offload aid, and for specifying aid design features that ensure that automation will provide effective operator support in a multitask environment.

scholarly journals Numerical Simulation Study for the Performance of a Large Solar Hot Water System With Horizontal Storage Tank

2015 ◽  
Author(s):  
Ru Yang ◽  
Geng-Yi Lin
Keyword(s):  
Numerical Simulation ◽  
System Performance ◽  
Storage Tank ◽  
Large Scale ◽  
Cooling System ◽  
Water System ◽  
Thermal Storage ◽  
Hot Water ◽  
Design Parameters ◽  
Total Load

A large solar hot water system can be utilized to provide driving energy for heating system, heat-driven cooling system, as well as to provide hot water. This research addresses the effects of the storage tank design parameters on the performance of a large-scale solar hot water system with a horizontal storage tank. Most literatures only considered the stratification performance of the thermal storage tank itself instead of considering the overall system performance. Also, there is lack of experimental research data available for the design purpose. Therefore, this study employs a numerical simulation technique to study the design parameters effect of a horizontal thermal storage tank on the performance of a large-scale solar hot water system. In this study, the ANSYS-CFX program is employed to calculate the flow and temperature distributions inside horizontal thermal storage tank. Then the inlets and outlets of the tank are combined with the TRNSYS program to simulate the entire system performance under the weather of three representative cities of Taiwan, (Taipei, Taichung and, Kaohsiung). The results of the present study indicate that the vertical stratification baffles in the tank have important effects on system performance improvement. Quantitative increase of solar fraction of the total load is obtained. The comparison with the system with vertical storage tank is provided. The results of the present study can provide important reference for the large solar hot water system design in improving system efficiency.

Thermodynamic Analysis of a Solar Zeolite Refrigeration System

1985 ◽  
Vol 107 (3) ◽  
pp. 189-195 ◽  
Author(s):  
S. C. Chang ◽  
J. A. Roux
Keyword(s):  
Ambient Temperature ◽  
Water Absorption ◽  
System Performance ◽  
Solar Collector ◽  
Design Parameters ◽  
Absorption Refrigeration ◽  
Refrigeration System ◽  
Absorption Data ◽  
Refrigeration Unit ◽  
Determine System

A solar zeolite-water absorption refrigeration unit was studied. Thermodynamic expressions were derived to predict the system performance. The operating range and optimum design parameters for the zeolite system were determined. The main parameters governing performance were: solar collector type, ambient temperature, and absorber properties. Results are shown for various solar collector types and various zeolite types. A desorption initiation temperature is shown to exist. The analysis is not based on empirical heat of absorption data, but rather on a zeolite properties relationship (log Pv versus 1/Tz) to determine system performance.

Identifying Key Parameters for Design Improvement in High-Dimensional Systems With Uncertainty

2014 ◽  
Vol 136 (4) ◽  
Author(s):  
Johannes Fender ◽  
L. Graff ◽  
H. Harbrecht ◽  
Markus Zimmermann
Keyword(s):  
Numerical Optimization ◽  
Solution Space ◽  
Design Criterion ◽  
Design Parameters ◽  
High Dimensional ◽  
Design Work ◽  
Good Design ◽  
Design Improvement ◽  
Front Structure ◽  
Key Parameter

Key parameters may be used to turn a bad design into a good design with comparatively little effort. The proposed method identifies key parameters in high-dimensional nonlinear systems that are subject to uncertainty. A numerical optimization algorithm seeks a solution space on which all designs are good, that is, they satisfy a specified design criterion. The solution space is box-shaped and provides target intervals for each parameter. A bad design may be turned into a good design by moving its key parameters into their target intervals. The solution space is computed so as to minimize the effort for design work: its shape is controlled by particular constraints such that it can be reached by changing only a small number of key parameters. Wide target intervals provide tolerance against uncertainty, which is naturally present in a design process, when design parameters are unknown or cannot be controlled exactly. In a simple two-dimensional example problem, the accuracy of the algorithm is demonstrated. In a high-dimensional vehicle crash design problem, an underperforming vehicle front structure is improved by identifying and appropriately changing a relevant key parameter.

scholarly journals PRESENSI SISWA MENGGUNAKAN QR CODE DAN SMS BROADCAST BERBASIS WEB

2019 ◽  
Vol 13 (1) ◽  
pp. 68-75
Author(s):  
Sherly Christina ◽  
Agus Sehatman Saragih ◽  
Fahrizal Maulana
Keyword(s):  
System Performance ◽  
Short Message Service ◽  
System Development ◽  
Black Box ◽  
Qr Code ◽  
Short Message ◽  
Student Attendance ◽  
Message Service ◽  
Black Box Testing ◽  
Development Phases

Student attendance is one of the factors that need to be controlled by the School to maintain Indonesian resources. Therefore a school needs a system that can be used, for handles the students attendance data and distributes it to the parents. This necessity can be facilitated by building an online attendance system for the students. The online attendance system uses QR Code and Broadcast Short Message Service (SMS). The online attendance system used Waterfall methodology phases  as the system development  phases. Afterward  the system performance is evaluated using the black-box testing. The results test using black-box testing show that the system can accomplish the purpose of this research to meet the need of the School in collecting the student attendance data and distributing the information of the students attendance data to the parents. This system uses QR Code and the results of collecting the student attendance data are sent by the system through Broadcast SMS to parents.

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