Multidiscipline Design Optimization

1988 ◽  
Vol 41 (6) ◽  
pp. 257-262 ◽  
Author(s):  
Garret N. Vanderplaats

While formal optimization techniques are seeing increasing use within individual disciplines, application of this technology to the more general multidiscipline design problem is less common. This is due to both the inherent complexity of multidiscipline design and the fact that design is traditionally separated along discipline lines. The application of optimization to multilevel and multidiscipline design is discussed here. It is seen that, computationally, multilevel design within a single discipline and multidiscipline design across disciplines have similar features, and so are generally treated the same. Multidiscipline optimization at the conceptual level is first discussed and it is seen that this has been done successfully for some time. Then the more general case is discussed where formal mathematical decomposition of the larger problem is required to make optimization practical. Here, the state of the art is still relatively undeveloped. Two basic approaches are briefly described to indicate the concepts, and a simple example is offered. The key idea in persuing the multidiscipline design problem is that the optimum system is seldom the sum of optimum components. It is necessary to properly account for the coupling that exists among the subsystems, while still allowing the individual designer to work with relative freedom within his discipline. It is concluded that to achieve this, considerable research remains ahead.

Author(s):  
James T. Allison ◽  
Sam Nazari

An often cited motivation for using decomposition-based optimization methods to solve engineering system design problems is the ability to apply discipline-specific optimization techniques. For example, structural optimization methods have been employed within a more general system design optimization framework. We propose an extension of this principle to a new domain: control design. The simultaneous design of a physical system and its controller is addressed here using a decomposition-based approach. An optimization subproblem is defined for both the physical system (i.e., plant) design and the control system design. The plant subproblem is solved using a general optimization algorithm, while the controls subproblem is solved using a new approach based on optimal control theory. The optimal control solution, which is derived using the the Minimum Principle of Pontryagin (PMP), accounts for coupling between plant and controller design by managing additional variables and penalty terms required for system coordination. Augmented Lagrangian Coordination is used to solve the system design problem, and is demonstrated using a circuit design problem.


2008 ◽  
Vol 130 (3) ◽  
Author(s):  
Hamid Hadim ◽  
Tohru Suwa

Electronics packaging design is a process that requires optimized solutions based on multidisciplinary design trade-offs, which usually have complex relationships among multiple design variables. Required numerical analyses combining electrical, thermal, and thermomechanical, among others, have made the multidisciplinary design and optimization process more challenging because of their time-intensive modeling and computation. In this paper, a state-of-the-art review of recent multidisciplinary design and optimization methodologies in electronics packaging is presented. The reported methodologies are divided into three groups: (1) integrated multidisciplinary computer aided design (CAD) environment, (2) semi-automated design optimization techniques, and (3) automated component placement techniques. In the first group, multidisciplinary design and optimization are carried out using interactive CAD environment software. The electronics packaging designer inputs data and makes decisions, while the CAD software provides a comprehensive multidisciplinary modeling and simulation environment. In the second group, using semi-automated design optimization methodologies, various objectives are optimized simultaneously mainly based on package configurations (dimensions), material properties, and operating conditions. In the third group, optimal placement of heat generating components is performed automatically based on multiple requirements. In recent years, methodologies using (1) detailed numerical analysis models directly connected to optimization algorithms, (2) design of experiments (DoE), and (3) artificial neural networks (ANNs) have been proposed as new trends in this field. These methodologies have led to significant improvement in design optimization capabilities, while they require intensive computational effort. Advantages as well as disadvantages of these methods are discussed.


2021 ◽  
Vol 9 (5) ◽  
pp. 478
Author(s):  
Hao Chen ◽  
Weikun Li ◽  
Weicheng Cui ◽  
Ping Yang ◽  
Linke Chen

Biomimetic robotic fish systems have attracted huge attention due to the advantages of flexibility and adaptability. They are typically complex systems that involve many disciplines. The design of robotic fish is a multi-objective multidisciplinary design optimization problem. However, the research on the design optimization of robotic fish is rare. In this paper, by combining an efficient multidisciplinary design optimization approach and a novel multi-objective optimization algorithm, a multi-objective multidisciplinary design optimization (MMDO) strategy named IDF-DMOEOA is proposed for the conceptual design of a three-joint robotic fish system. In the proposed IDF-DMOEOA strategy, the individual discipline feasible (IDF) approach is adopted. A novel multi-objective optimization algorithm, disruption-based multi-objective equilibrium optimization algorithm (DMOEOA), is utilized as the optimizer. The proposed MMDO strategy is first applied to the design optimization of the robotic fish system, and the robotic fish system is decomposed into four disciplines: hydrodynamics, propulsion, weight and equilibrium, and energy. The computational fluid dynamics (CFD) method is employed to predict the robotic fish’s hydrodynamics characteristics, and the backpropagation neural network is adopted as the surrogate model to reduce the CFD method’s computational expense. The optimization results indicate that the optimized robotic fish shows better performance than the initial design, proving the proposed IDF-DMOEOA strategy’s effectiveness.


2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Xudong Zhu ◽  
Zhiyang Chen ◽  
Weiyan Shen ◽  
Gang Huang ◽  
John M. Sedivy ◽  
...  

AbstractRemarkable progress in ageing research has been achieved over the past decades. General perceptions and experimental evidence pinpoint that the decline of physical function often initiates by cell senescence and organ ageing. Epigenetic dynamics and immunometabolic reprogramming link to the alterations of cellular response to intrinsic and extrinsic stimuli, representing current hotspots as they not only (re-)shape the individual cell identity, but also involve in cell fate decision. This review focuses on the present findings and emerging concepts in epigenetic, inflammatory, and metabolic regulations and the consequences of the ageing process. Potential therapeutic interventions targeting cell senescence and regulatory mechanisms, using state-of-the-art techniques are also discussed.


2016 ◽  
Vol 55 (3) ◽  
pp. 1091-1119 ◽  
Author(s):  
Jianguang Fang ◽  
Guangyong Sun ◽  
Na Qiu ◽  
Nam H. Kim ◽  
Qing Li

1978 ◽  
Vol 3 (3) ◽  
pp. 148-159 ◽  
Author(s):  
Howard S. Adelman

Presented are (1) a brief synthesis of several key conceptual and methodological concerns and some ethical perspectives related to identification of psycho-educational problems and (2) conclusions regarding the current state of the art. The conceptual discussion focuses on differentiating prediction from identification and screening from diagnosis; three models used in developing assessment procedures also are presented. Methodologically, the minimal requirements for satisfactory research are described and current problems are highlighted. Three ethical perspectives are discussed; cost-benefit for the individual, models-motives-goals underlying practices, and cost-benefit for the culture. The current state of the art is seen as not supporting the efficacy of the widespread use of currently available procedures for mass screening. Given this point and the methodological and ethical concerns discussed, it is suggested that policy makers reallocate limited resources away from mass identification and toward health maintenance and other approaches to prevention and early-age intervention.


2017 ◽  
Vol 18 (2) ◽  
pp. 107-117 ◽  
Author(s):  
György Kovács

Abstract The transport activity is one of the most expensive processes in the supply chain. Forwarding and transport companies focuses on the optimization of transportation and the reduction of transport costs. The goal of this study is to develop a method which calculate the first (prime) cost of a given transport task more precisely than the state of the art practices. In practice the calculation of transport fee depends on the individual estimation methods of the transport managers, which could result losses for the company. In this study the elaborated calculation method for total first cost is detailed for three types of fulfilment of transport tasks. The most common type of achievement is, when “own vehicle is used with own driver”. A software was also developed for this case based on the elaborated method. Based on the calculations of our software, the first cost can be defined quickly and precisely to realize higher profit.


Author(s):  
Trung Minh Nguyen ◽  
Thien Huu Nguyen

The previous work for event extraction has mainly focused on the predictions for event triggers and argument roles, treating entity mentions as being provided by human annotators. This is unrealistic as entity mentions are usually predicted by some existing toolkits whose errors might be propagated to the event trigger and argument role recognition. Few of the recent work has addressed this problem by jointly predicting entity mentions, event triggers and arguments. However, such work is limited to using discrete engineering features to represent contextual information for the individual tasks and their interactions. In this work, we propose a novel model to jointly perform predictions for entity mentions, event triggers and arguments based on the shared hidden representations from deep learning. The experiments demonstrate the benefits of the proposed method, leading to the state-of-the-art performance for event extraction.


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