Bi-level Approach to Vehicle Component Layout With Shape Morphing

2011 ◽  
Vol 133 (4) ◽  
Author(s):  
Hong Dong ◽  
Paolo Guarneri ◽  
Georges Fadel
Keyword(s):  
Large Scale ◽  
Layout Design ◽  
System Level ◽  
Component Level ◽  
Packing Problems ◽  
Engineering Research ◽  
Shape Morphing ◽  
Design Variables ◽  
Component Layout ◽  
Overall Performance

Engineering research into packing problems has been widely undertaken in recent years. The use of component shape morphing in layout design has, however, received little attention. Shape morphing is required for fitting a component of sufficient size in a limited space while optimizing the overall performance objectives of the vehicle and improving design efficiency. To morph components that can have arbitrary shapes in layout design, a mass-spring physical model-based morphing method is proposed and implemented. Vehicle layout design with shape morphing is a multi-objective, multilevel problem with a large number of design variables. To solve this large scale problem, decomposition is adopted. At the system level, the overall performance objectives are optimized with respect to locations and orientations of components. At the component level, deformable objects are morphed to fit in the available space. A vehicle underhood layout design problem is demonstrated to illustrate the proposed approach.

Vehicle Component Layout With Shape Morphing: An Initial Study

2006 ◽  
Author(s):  
Hong Dong ◽  
Georges M. Fadel ◽  
Vincent Y. Blouin
Keyword(s):  
Initial Study ◽  
Complex Problem ◽  
Layout Design ◽  
System Level ◽  
Component Level ◽  
Improve Design ◽  
Shape Morphing ◽  
Advantages And Disadvantages ◽  
Component Layout ◽  
Component Shape

This work focuses on incorporating component shape design into a vehicle configuration design or layout process. A concurrent design process consisting of performing layout design and simultaneous shape morphing of some select components is adopted to replace the traditional sequential design approach. The objective is to improve design efficiency and reduce design cost. Two important issues in the packing optimization with shape morphing problem are identified and studied: the morphing and the optimization. A parameterization-based morphing method and a mesh-based morphing method are implemented, and their advantages and disadvantages are discussed. To efficiently solve this complex problem, it is proposed to decompose it into a bi-level formulation: system level and component level. At the system level, the given functional objectives of the layout design problem are optimized with respect to component positions and orientations. At the component level, the shape of select components is morphed to minimize the overlap with other objects and the enclosure. By iterating between these two levels, the original problem is solved. This bi-level approach is intended to overcome the complexity of performing the placement simultaneously with the shape morphing.

scholarly journals Interaction Prediction Optimization in Multidisciplinary Design Optimization Problems

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Debiao Meng ◽  
Xiaoling Zhang ◽  
Hong-Zhong Huang ◽  
Zhonglai Wang ◽  
Huanwei Xu
Keyword(s):  
Interaction Design ◽  
Large Scale ◽  
Optimization Problems ◽  
Collaborative Optimization ◽  
System Level ◽  
Design Parameters ◽  
Large Scale Systems ◽  
Interaction Prediction ◽  
Design Variables ◽  
Subsystem Level

The distributed strategy of Collaborative Optimization (CO) is suitable for large-scale engineering systems. However, it is hard for CO to converge when there is a high level coupled dimension. Furthermore, the discipline objectives cannot be considered in each discipline optimization problem. In this paper, one large-scale systems control strategy, the interaction prediction method (IPM), is introduced to enhance CO. IPM is utilized for controlling subsystems and coordinating the produce process in large-scale systems originally. We combine the strategy of IPM with CO and propose the Interaction Prediction Optimization (IPO) method to solve MDO problems. As a hierarchical strategy, there are a system level and a subsystem level in IPO. The interaction design variables (including shared design variables and linking design variables) are operated at the system level and assigned to the subsystem level as design parameters. Each discipline objective is considered and optimized at the subsystem level simultaneously. The values of design variables are transported between system level and subsystem level. The compatibility constraints are replaced with the enhanced compatibility constraints to reduce the dimension of design variables in compatibility constraints. Two examples are presented to show the potential application of IPO for MDO.

scholarly journals New developments in battery safety for large-scale systems

MRS Bulletin ◽  
2021 ◽  
Author(s):  
Joshua Lamb ◽  
Judith A. Jeevarajan
Keyword(s):  
Large Scale ◽  
New Technologies ◽  
Lithium Ion ◽  
High Energy ◽  
Rechargeable Batteries ◽  
System Level ◽  
Component Level ◽  
Emergent Technologies ◽  
Battery Safety ◽  
The Individual

AbstractBattery safety is a multidisciplinary field that involves addressing challenges at the individual component level, cell level, as well as the system level. These concerns are magnified when addressing large, high-energy battery systems for grid-scale, electric vehicle, and aviation applications. This article seeks to introduce common concepts in battery safety as well as common technical concerns in the safety of large rechargeable systems. Lithium-ion batteries represent the most significant technology in high-energy rechargeable batteries and a technology with well-known safety concerns. Because of this, particular attention is paid to introduce common concepts and concerns specific to these batteries. An introduction of system-level battery issues that may cause problems in larger systems is given. Finally, a brief summary of the gaps in emergent technologies is provided. As most of the effort in new technologies goes toward improving performance, there are significant gaps in understanding safety performance of these new batteries.

Optimum design of composite structures subjected to multiple displacement constraints

1993 ◽  
Vol 28 (2) ◽  
pp. 135-141 ◽  
Author(s):  
W J Li ◽  
J Y Chen
Keyword(s):  
Optimum Design ◽  
Composite Structures ◽  
Optimization Technique ◽  
Energy Criterion ◽  
System Level ◽  
Multilevel Optimization ◽  
Component Level ◽  
Design Variables ◽  
Displacement Constraints ◽  
Criterion Method

The paper presents an effective method for achieving the optimum design of composite structures subjected to multiple displacement constraints. Based on the optimality criterion method and some approximate engineering assumptions, this paper introduces a simplified expression relating the design variables to Lagrange multipliers, which correspond to displacement constraints. Therefore, the optimal design variables are derived from a smaller number of unknown coefficients. Thus the computational efficiency is greatly enhanced. Furthermore, the multilevel optimization technique is adopted. The optimum design variables are obtained in system level optimization. For more detailed design the ply thicknesses of a composite plate are adjusted in component level optimization by using the maximum strain energy criterion. A cantilever composite beam, subjected to strength and multiple displacement constraints, is studied as the illustrative example. The computational results indicate the efficiency of the method.

Dynamic Infrared System Level Fault Isolation

2003 ◽  
Author(s):  
John A. Naoum ◽  
Johan Rahardjo ◽  
Yitages Taffese ◽  
Marie Chagny ◽  
Jeff Birdsley ◽  
...  
Keyword(s):  
Fault Isolation ◽  
System Level ◽  
System Component ◽  
Component Level ◽  
Ir Imaging ◽  
Non Destructive

Abstract The use of Dynamic Infrared (IR) Imaging is presented as a novel, valuable and non-destructive approach for the analysis and isolation of failures at a system/component level.

Building a Culture of Ethical, Comparable, Authentic Assessment

2019 ◽  
pp. 463-481
Author(s):  
Andrew Reid ◽  
Julie Ballantyne
Keyword(s):  
Teaching And Learning ◽  
Large Scale ◽  
Authentic Assessment ◽  
Subject Area ◽  
Music Educators ◽  
System Level ◽  
Diverse Range ◽  
Effective Learning ◽  
School Based ◽  
The Subject

In an ideal world, assessment should be synonymous with effective learning and reflect the intricacies of the subject area. It should also be aligned with the ideals of education: to provide equitable opportunities for all students to achieve and to allow both appropriate differentiation for varied contexts and students and comparability across various contexts and students. This challenge is made more difficult in circumstances in which the contexts are highly heterogeneous, for example in the state of Queensland, Australia. Assessment in music challenges schooling systems in unique ways because teaching and learning in music are often naturally differentiated and diverse, yet assessment often calls for standardization. While each student and teacher has individual, evolving musical pathways in life, the syllabus and the system require consistency and uniformity. The challenge, then, is to provide diverse, equitable, and quality opportunities for all children to learn and achieve to the best of their abilities. This chapter discusses the designing and implementation of large-scale curriculum as experienced in secondary schools in Queensland, Australia. The experiences detailed explore the possibilities offered through externally moderated school-based assessment. Also discussed is the centrality of system-level clarity of purpose, principles and processes, and the provision of supportive networks and mechanisms to foster autonomy for a diverse range of music educators and contexts. Implications for education systems that desire diversity, equity, and quality are discussed, and the conclusion provokes further conceptualization and action on behalf of students, teachers, and the subject area of music.

scholarly journals Reliability Analysis and Repair Activity for the Components of 350 kW Inverters in a Large Scale Grid-Connected Photovoltaic System

Electronics ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 564
Author(s):  
Filippo Spertino ◽  
Angela Amato ◽  
Gabriele Casali ◽  
Alessandro Ciocia ◽  
Gabriele Malgaroli
Keyword(s):  
Reliability Analysis ◽  
Large Scale ◽  
Photovoltaic System ◽  
Component Level ◽  
Ac Power ◽  
Repair Activity ◽  
Industrial Maintenance ◽  
Large Scale Grid ◽  
Ac Converters ◽  
Scale Grid

The reliability of photovoltaic (PV) generators is strongly affected by the performance of Direct Current/Alternating Current (DC/AC) converters, being the major source of PV underperformance. However, generally, their reliability is not investigated at component level: thus, the present work presents a reliability analysis and the repair activity for the components of full bridge DC/AC converters. In the first part of the paper, a reliability analysis using failure rates from literature is carried out for 132 inverters (AC rated power of 350 kW each) with global AC power of 46 MW in a large scale grid-connected PV plant. Then, in the second part of the work, results from literature are compared with data obtained by analyzing industrial maintenance reports in the years 2015–2017. In conclusion, the yearly energy losses involved in the downtime are quantified, as well as their availability.

scholarly journals Drug Prescription Profiles in Patients with Polypharmacy in Spain: A Large-Scale Pharmacoepidemiologic Study Using Real-World Data

2021 ◽  
Vol 18 (9) ◽  
pp. 4754
Author(s):  
Miguel Ángel Hernández-Rodríguez ◽  
Ermengol Sempere-Verdú ◽  
Caterina Vicens-Caldentey ◽  
Francisca González-Rubio ◽  
Félix Miguel-García ◽  
...  
Keyword(s):  
Psychotropic Drugs ◽  
Large Scale ◽  
Anatomical Therapeutic Chemical ◽  
Drug Prescription ◽  
Age Groups ◽  
System Level ◽  
Real World Data ◽  
Converting Enzyme Inhibitors ◽  
Cross Sectional ◽  
Β Blockers

We aimed to identify and compare medication profiles in populations with polypharmacy between 2005 and 2015. We conducted a cross-sectional study using information from the Computerized Database for Pharmacoepidemiologic Studies in Primary Care (BIFAP, Spain). We estimated the prevalence of therapeutic subgroups in all individuals 15 years of age and older with polypharmacy (≥5 drugs during ≥6 months) using the Anatomical Therapeutic Chemical classification system level 4, by sex and age group, for both calendar years. The most prescribed drugs were proton-pump inhibitors (PPIs), statins, antiplatelet agents, benzodiazepine derivatives, and angiotensin-converting enzyme inhibitors. The greatest increases between 2005 and 2015 were observed in PPIs, statins, other antidepressants, and β-blockers, while the prevalence of antiepileptics was almost tripled. We observed increases in psychotropic drugs in women and cardiovascular medications in men. By patient´s age groups, there were notable increases in antipsychotics, antidepressants, and antiepileptics (15–44 years); antidepressants, PPIs, and selective β-blockers (45–64 years); selective β-blockers, biguanides, PPIs, and statins (65–79 years); and in statins, selective β-blockers, and PPIs (80 years and older). Our results revealed important increases in the use of specific therapeutic subgroups, like PPIs, statins, and psychotropic drugs, highlighting opportunities to design and implement strategies to analyze such prescriptions’ appropriateness.

scholarly journals Modelling and pH Control in Raceway and Thin-Layer Photobioreactors for Wastewater Treatment

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1099
Author(s):  
María José Rodríguez-Torres ◽  
Ainoa Morillas-España ◽  
José Luis Guzmán ◽  
Francisco Gabriel Acién
Keyword(s):  
Wastewater Treatment ◽  
Thin Layer ◽  
Large Scale ◽  
Control Period ◽  
Ph Control ◽  
Thin Layers ◽  
Control Algorithms ◽  
Treatment Processes ◽  
Overall Performance ◽  
Reduction Of Co2

One of the most critical variables in microalgae-related processes is the pH; it directly determines the overall performance of the production system especially when coupling with wastewater treatment. In microalgae-related wastewater treatment processes, the adequacy of pH has a large impact on the microalgae/bacteria consortium already developing on these systems. For cost-saving reasons, the pH is usually controlled by classical On/Off control algorithms during the daytime period, typically with the dynamics of the system and disturbances not being considered in the design of the control system. This paper presents the modelling and pH control in open photobioreactors, both raceway and thin-layer, using advanced controllers. In both types of photobioreactors, a classic control was implemented and compared with a Proportional–Integral (PI) control, also the operation during only the daylight period and complete daily time was evaluated. Thus, three major variables already studied include (i) the type of reactors (thin-layers and raceways), (ii) the type of control algorithm (On/Off and PI), and (iii) the control period (during the daytime and throughout the daytime and nighttime). Results show that the pH was adequately controlled in both photobioreactors, although each type requires different control algorithms, the pH control being largely improved when using PI controllers, with the controllers allowing us to reduce the total costs of the process with the reduction of CO2 injections. Moreover, the control during the complete daily cycle (including night) not only not increases the amount of CO2 to be injected, otherwise reducing it, but also improves the overall performance of the production process. Optimal pH control systems here developed are highly useful to develop robust large-scale microalgae-related wastewater treatment processes.

scholarly journals Integration of enzyme constraints in a genome-scale metabolic model of Aspergillus niger improves phenotype predictions

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Jingru Zhou ◽  
Yingping Zhuang ◽  
Jianye Xia
Keyword(s):  
Aspergillus Niger ◽  
Large Scale ◽  
Measurement Techniques ◽  
Metabolic Model ◽  
System Level ◽  
Metabolic Phenotype ◽  
Omics Data ◽  
Prediction Ability ◽  
Phenotype Prediction ◽  
Genome Scale

Abstract Background Genome-scale metabolic model (GSMM) is a powerful tool for the study of cellular metabolic characteristics. With the development of multi-omics measurement techniques in recent years, new methods that integrating multi-omics data into the GSMM show promising effects on the predicted results. It does not only improve the accuracy of phenotype prediction but also enhances the reliability of the model for simulating complex biochemical phenomena, which can promote theoretical breakthroughs for specific gene target identification or better understanding the cell metabolism on the system level. Results Based on the basic GSMM model iHL1210 of Aspergillus niger, we integrated large-scale enzyme kinetics and proteomics data to establish a GSMM based on enzyme constraints, termed a GEM with Enzymatic Constraints using Kinetic and Omics data (GECKO). The results show that enzyme constraints effectively improve the model’s phenotype prediction ability, and extended the model’s potential to guide target gene identification through predicting metabolic phenotype changes of A. niger by simulating gene knockout. In addition, enzyme constraints significantly reduced the solution space of the model, i.e., flux variability over 40.10% metabolic reactions were significantly reduced. The new model showed also versatility in other aspects, like estimating large-scale $$k_{{cat}}$$ k cat values, predicting the differential expression of enzymes under different growth conditions. Conclusions This study shows that incorporating enzymes’ abundance information into GSMM is very effective for improving model performance with A. niger. Enzyme-constrained model can be used as a powerful tool for predicting the metabolic phenotype of A. niger by incorporating proteome data. In the foreseeable future, with the fast development of measurement techniques, and more precise and rich proteomics quantitative data being obtained for A. niger, the enzyme-constrained GSMM model will show greater application space on the system level.

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