Reflections on Engineering Systems and Bond Graphs

1993 ◽  
Vol 115 (2B) ◽  
pp. 242-251 ◽  
Author(s):  
R. C. Rosenberg
Keyword(s):  
Mechanical Engineer ◽  
Problem Solving ◽  
Large Scale ◽  
Bond Graph ◽  
Engineering System ◽  
Engineering Systems ◽  
Bond Graphs ◽  
Modern Engineering ◽  
Versatile Tool ◽  
Systems Simulation

An important aspect of modern engineering systems is their great diversity. Often they include interactions among different physical domains, contain control subsystems, and are large-scale and complex. The bond graph is a powerful and versatile tool that can help the engineer to design modern engineering systems. Three issues are explored from a bond graph perspective: modeling of engineering systems, simulation of their behavior, and teaching about engineering systems. It is the author’s observation that bond graph methodology is one of the most useful engineering system techniques available and belongs in the problem-solving tool kit of every mechanical engineer. This paper develops a rationale for this viewpoint both for readers familiar with bond graph methods and for readers to whom they are new.

The Bond Graph as a Unified Data Base for Engineering System Design

1975 ◽  
Vol 97 (4) ◽  
pp. 1333-1337 ◽  
Author(s):  
R. C. Rosenberg
Keyword(s):  
Data Base ◽  
Large Scale ◽  
Dynamic Models ◽  
Systems Design ◽  
Bond Graph ◽  
Graph Representation ◽  
Model Description ◽  
Engineering System ◽  
State Equations ◽  
Engineering System Design

In developing a unified data base for support of engineering systems design there are several important factors to consider, such as efficiency of model description, ease of modifying models, and characteristics of assembling device models into systems. The multipart model and its associated bond graph representation can serve very effectively as a unified data base, especially when devices and systems involve several energy domains simultaneously (e.g., electromechanical or hydromechanical transduction). In addition to providing a succinct, flexible data base for linear and nonlinear, static and dynamic models, bond graphs can be processed causally to reveal important information about alternative input-output choices and device-level coupling factors when submodels are assembled into systems. Particularly for large-scale nonlinear systems this is an important feature in aiding the formulation of state equations. Illustrations of the bond graph data base approach are given.

Collaborative design process of large-scale engineering systems using the axiomatic design approach

2011 ◽  
Vol 225 (9) ◽  
pp. 2174-2188 ◽  
Author(s):  
E-P Hong ◽  
G-J Park
Keyword(s):  
Electric Vehicle ◽  
Design Process ◽  
Collaborative Design ◽  
Large Scale ◽  
Axiomatic Design ◽  
Independence Axiom ◽  
Functional Domain ◽  
Engineering System ◽  
Design Teams ◽  
Engineering Systems

The complexity of engineering systems is rapidly increasing because the number of components has increased and various engineering disciplines are involved. According to this trend, large-scale engineering systems are designed by multiple design teams with many designers of various disciplines. Although the design process by the design teams is a great deal similar to the design process by an individual designer, there is an important difference between them. Designing a large-scale engineering system with design teams can cause potential conflict among the subsystems because each team may design a subsystem without considering the other team’s subsystems. In this article, a collaborative design process is proposed to design a large-scale engineering system efficiently without the conflict among the subsystems using the Independence Axiom of axiomatic design. The proposed process uses a zigzagging process between the functional domain and the physical domain, and the online electric vehicle (OLEV) is designed by the proposed process. The OLEV is an electric vehicle which uses electric power transmitted wirelessly from the power source buried in the road. The functional requirements (FRs) and constraints of the OLEV are specified to clarify the design objectives and specifications. The prototype, which is designed by the design teams based on the defined FRs, is evaluated using the proposed process. It is found that the proposed process can lead design teams to design a product more efficiently without unnecessary iterations.

scholarly journals Information Fusion for National Airspace System Prognostics

2018 ◽  
Vol 10 (1) ◽  
Author(s):  
Yongming Liu ◽  
Kai Goebel
Keyword(s):  
Information Fusion ◽  
Large Scale ◽  
Health Management ◽  
Engineering System ◽  
Human Computer Interface ◽  
Engineering Systems ◽  
National Airspace System ◽  
University Leadership ◽  
Collaborative Project ◽  
Fully Coupled

Expanding Prognostics and Health Management (PHM) from an equipment-centric view to complex large-scale engineering systems is a challenging problem. One example for a large engineering system is the next generation national airspace system (NAS), which is a fully coupled cyberphysical- human system. This paper presents an overview of a NASA University Leadership Initiative (ULI) project which aims to address the safety needs and their technology solutions for future NAS. The ULI is a 5-year collaborative project in which researchers from several universities and commercial entities work together to advance real-time airspace safety concepts. The underlying premise is that it is imperative to be able to assess and predict the evolution of the airspace’s safety state. Towards that end the work envisions to address the following issues: modeling of the airspace using both data-driven and physics based approaches; quantifying and managing uncertainty; advancing prognostics and information fusion algorithms; and understanding and modeling human computer interface. A comprehensive simulation environment is being built that allows for assessment of performance and verification and validation. The paper discusses the various activities and places them into the context of overall NAS safety.

scholarly journals Energy-based analysis of biochemical cycles using bond graphs

2014 ◽  
Vol 470 (2171) ◽  
pp. 20140459 ◽  
Author(s):  
Peter J. Gawthrop ◽  
Edmund J. Crampin
Keyword(s):  
Chemical Potential ◽  
Simulation Models ◽  
Bond Graph ◽  
Biochemical Networks ◽  
Engineering Systems ◽  
Bond Graphs ◽  
Secure Foundation ◽  
Biochemical Systems ◽  
Gibb’S Free Energy

Thermodynamic aspects of chemical reactions have a long history in the physical chemistry literature. In particular, biochemical cycles require a source of energy to function. However, although fundamental, the role of chemical potential and Gibb's free energy in the analysis of biochemical systems is often overlooked leading to models which are physically impossible. The bond graph approach was developed for modelling engineering systems, where energy generation, storage and transmission are fundamental. The method focuses on how power flows between components and how energy is stored, transmitted or dissipated within components. Based on the early ideas of network thermodynamics, we have applied this approach to biochemical systems to generate models which automatically obey the laws of thermodynamics. We illustrate the method with examples of biochemical cycles. We have found that thermodynamically compliant models of simple biochemical cycles can easily be developed using this approach. In particular, both stoichiometric information and simulation models can be developed directly from the bond graph. Furthermore, model reduction and approximation while retaining structural and thermodynamic properties is facilitated. Because the bond graph approach is also modular and scaleable, we believe that it provides a secure foundation for building thermodynamically compliant models of large biochemical networks.

Structure Graphs: A New Approach for Interactive Computer Modelling of Multi-Energy Domain Systems

1982 ◽  
Vol 104 (2) ◽  
pp. 143-150 ◽  
Author(s):  
R. Liebner ◽  
F. Abdullah ◽  
L. Finkelstein
Keyword(s):  
Computer Modelling ◽  
Engineering System ◽  
Engineering Systems ◽  
Bond Graphs ◽  
Signal Flow Graphs ◽  
Lumped Parameter ◽  
Energy Domain ◽  
Interactive Modelling ◽  
Linear Graphs ◽  
Flow Graphs

A computer package MEDIEM (Multi-Energy Domain Interactive Element Modelling) has been developed and mounted on a minicomputer for the purpose of interactive modelling of multi-energy domain engineering systems. The basis of the package is a graphical language called “structure graphs” which allows the user to model the “structure” or essential features of a lumped parameter engineering system in close correspondence to a schematic. It is shown that structure graphs arise naturally when modelling is considered within an interactive computer-aided environment. The approach has certain advantages over those based on current techniques such as bond graphs, linear graphs, and signal flow graphs; the main ones being the ease of model construction and the ease of effecting model changes (both structural and parameter changes). The package will handle both linear and nonlinear systems. Some illustrative examples of the use of structure graphs are provided together with a detailed example of the use of MEDIEM for modelling a complex differential pressure transducer. Lastly some special causal problems reported in the bond graph literature are examined and shown not to exist when MEDIEM is used.

scholarly journals Using process data to understand problem-solving strategies and processes for drag-and-drop items in a large-scale mathematics assessment

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Yang Jiang ◽  
Tao Gong ◽  
Luis E. Saldivia ◽  
Gabrielle Cayton-Hodges ◽  
Christopher Agard
Keyword(s):  
Problem Solving ◽  
Time Allocation ◽  
Large Scale ◽  
Solution Process ◽  
Process Data ◽  
Mathematics Assessments ◽  
Assessment Design ◽  
Eighth Grade Students ◽  
Problem Solving Strategies ◽  
Drag And Drop

AbstractIn 2017, the mathematics assessments that are part of the National Assessment of Educational Progress (NAEP) program underwent a transformation shifting the administration from paper-and-pencil formats to digitally-based assessments (DBA). This shift introduced new interactive item types that bring rich process data and tremendous opportunities to study the cognitive and behavioral processes that underlie test-takers’ performances in ways that are not otherwise possible with the response data alone. In this exploratory study, we investigated the problem-solving processes and strategies applied by the nation’s fourth and eighth graders by analyzing the process data collected during their interactions with two technology-enhanced drag-and-drop items (one item for each grade) included in the first digital operational administration of the NAEP’s mathematics assessments. Results from this research revealed how test-takers who achieved different levels of accuracy on the items engaged in various cognitive and metacognitive processes (e.g., in terms of their time allocation, answer change behaviors, and problem-solving strategies), providing insights into the common mathematical misconceptions that fourth- and eighth-grade students held and the steps where they may have struggled during their solution process. Implications of the findings for educational assessment design and limitations of this research are also discussed.

scholarly journals LncGSEA: a versatile tool to infer lncRNA associated pathways from large-scale cancer transcriptome sequencing data

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Yanan Ren ◽  
Ting-You Wang ◽  
Leah C. Anderton ◽  
Qi Cao ◽  
Rendong Yang
Keyword(s):  
Gene Expression ◽  
Large Scale ◽  
Expression Profiles ◽  
Gene Expression Profiles ◽  
Clinical Samples ◽  
Sequencing Data ◽  
Multiple Cancer ◽  
Regulatory Pathways ◽  
Cancer Transcriptome ◽  
Versatile Tool

Abstract Background Long non-coding RNAs (lncRNAs) are a growing focus in cancer research. Deciphering pathways influenced by lncRNAs is important to understand their role in cancer. Although knock-down or overexpression of lncRNAs followed by gene expression profiling in cancer cell lines are established approaches to address this problem, these experimental data are not available for a majority of the annotated lncRNAs. Results As a surrogate, we present lncGSEA, a convenient tool to predict the lncRNA associated pathways through Gene Set Enrichment Analysis of gene expression profiles from large-scale cancer patient samples. We demonstrate that lncGSEA is able to recapitulate lncRNA associated pathways supported by literature and experimental validations in multiple cancer types. Conclusions LncGSEA allows researchers to infer lncRNA regulatory pathways directly from clinical samples in oncology. LncGSEA is written in R, and is freely accessible at https://github.com/ylab-hi/lncGSEA.

scholarly journals Control method for the stable operation of distributed inverters following the introduction of large-scale renewable energy to a remote island grid

Clean Energy ◽  
2021 ◽  
Vol 5 (2) ◽  
pp. 196-207
Author(s):  
Shoichi Sato ◽  
Yasuhiro Noro
Keyword(s):  
Renewable Energy ◽  
Large Scale ◽  
Control Method ◽  
Synchronous Generator ◽  
Stable Operation ◽  
Battery Energy Storage Systems ◽  
Simulation Results ◽  
Battery Energy ◽  
Systems Simulation ◽  
Different Characteristics

Abstract The introduction of large-scale renewable energy requires a control system that can operate multiple distributed inverters in a stable way. This study proposes an inverter control method that uses information corresponding to the inertia of the synchronous generator to coordinate the operation of battery energy storage systems. Simulation results for a system with multiple inverters applying the control method are presented. Various faults such as line-to-line short circuits and three-phase line-to-ground faults were simulated. Two fault points with different characteristics were compared. The voltage, frequency and active power quickly returned to their steady-state values after the fault was eliminated. From the obtained simulation results, it was verified that our control method can be operated stably against various faults.

Bond Graph Sign Conventions

1975 ◽  
Vol 97 (2) ◽  
pp. 184-188 ◽  
Author(s):  
A. S. Perelson
Keyword(s):  
Graph Model ◽  
Bond Graph ◽  
Equivalence Classes ◽  
Parameter System ◽  
Bond Graphs ◽  
Lumped Parameter ◽  
Oriented Object

The lack of arbitrariness in the choice of bond graph sign conventions is established. It is shown that an unoriented bond graph may have no unique meaning and that with certain choices of orientation a bond graph may not correspond to any lumped parameter system constructed from the same set of elements. Network interpretations of these two facts are given. Defining a bond graph as an oriented object leads to the consideration of equivalence classes of oriented bond graphs which represent the same system. It is also shown that only changes in the orientation of bonds connecting 0-junctions and 1-junctions can lead to changes in the observable properties of a bond graph model.

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