scholarly journals Function modeling using the system state flow diagram

2017 ◽  
Vol 31 (4) ◽  
pp. 413-435 ◽  
Author(s):  
Unal Yildirim ◽  
Felician Campean ◽  
Huw Williams
Keyword(s):  
Case Studies ◽  
Critical Evaluation ◽  
Decomposition Analysis ◽  
Flow Diagram ◽  
System State ◽  
Modeling Framework ◽  
Industrial Case Study ◽  
Modeling And Analysis ◽  
State Flow ◽  
Function Decomposition

AbstractThis paper introduces a rigorous framework for function modeling of complex multidisciplinary systems based on the system state flow diagram (SSFD). The work addresses the need for a consistent methodology to support solution-neutral function-based system decomposition analysis, facilitating the design, modeling, and analysis of complex systems architectures. A rigorous basis for the SSFD is established by defining conventions for states and function definitions and a representation scheme, underpinned by a critical review of existing literature. A set of heuristics are introduced to support the function decomposition analysis and to facilitate the deployment of the methodology with strong practitioner guidelines. The SSFD heuristics extend the existing framework of Otto and Wood (2001) by introducing a conditional fork node heuristic, to facilitate analysis and aggregation of function models across multiple modes of operation of the system. The empirical validation of the SSFD function modeling framework is discussed in relation to its application to two case studies: a benchmark problem (glue gun) set for the engineering design community; and an industrial case study of an electric vehicle powertrain. Based on the evidence from the two case studies presented in the paper, a critical evaluation of the SSFD function modeling methodology is discussed based on the function benchmarking framework established by Summers et al. (2013), considering the representation, modeling, cognitive, and reasoning characteristics. The significance of this paper is that it establishes a rigorous reference framework for the SSFD function representation and a consistent methodology to guide the practitioner with its deployment, facilitating its impact to industrial practice.

The traceback method and the early constructicon: theoretical and methodological considerations

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Nikolas Koch ◽  
Stefan Hartmann ◽  
Antje Endesfelder Quick
Keyword(s):  
Language Acquisition ◽  
Case Studies ◽  
Child Language ◽  
Critical Evaluation ◽  
Methodological Choices ◽  
Corpus Data ◽  
Methodological Considerations ◽  
Language Corpus

AbstractUsage-based approaches assume that children’s early utterances are item-based. This has been demonstrated in a number of studies using the traceback method. In this approach, a small amount of “target utterances” from a child language corpus is “traced back” to earlier utterances. Drawing on a case study of German, this paper provides a critical evaluation of the method from a usage-based perspective. In particular, we check how factors inherent to corpus data as well as methodological choices influence the results of traceback studies. To this end, we present four case studies in which we change thresholds and the composition of the main corpus, use a cross-corpus approach tracing one child’s utterances back to another child’s corpus, and reverse and randomize the target utterances. Overall, the results show that the method can provide interesting insights—particularly regarding different pathways of language acquisition—but they also show the limitations of the method.

scholarly journals Engineering Design Tools for Shape Memory Alloy Actuators: CASMART Collaborative Best Practices and Case Studies

2016 ◽  
Author(s):  
Robert W. Wheeler ◽  
Othmane Benafan ◽  
Xiujie Gao ◽  
Frederick T. Calkins ◽  
Zahra Ghanbari ◽  
...  
Keyword(s):  
Shape Memory Alloy ◽  
Best Practices ◽  
Shape Memory ◽  
Case Studies ◽  
Design Parameters ◽  
Solar Array ◽  
Design Tools ◽  
Modeling Framework ◽  
Modeling Tools ◽  
Actuation System

The primary goal of the Consortium for the Advancement of Shape Memory Alloy Research and Technology (CASMART) is to enable the design of revolutionary applications based on shape memory alloy (SMA) technology. In order to help realize this goal and reduce the development time and required experience for the fabrication of SMA actuation systems, several modeling tools have been developed for common actuator types and are discussed herein along with case studies, which highlight the capabilities and limitations of these tools. Due to their ability to sustain high stresses and recover large deformations, SMAs have many potential applications as reliable, lightweight, solid-state actuators. Their advantage over classical actuators can also be further improved when the actuator geometry is modified to fit the specific application. In this paper, three common actuator designs are studied: wires, which are lightweight, low-profile, and easily implemented; springs, which offer actuation strokes upwards of 200% at reduced mechanical loads; and torque tubes, which can provide large actuation forces in small volumes and develop a repeatable zero-load actuation response (known as the two-way shape memory effect). The modeling frameworks, which have been implemented in the design tools, are developed for each of these frequently used SMA actuator types. In order to demonstrate the versatility and flexibility of the presented design tools, as well as validate their modeling framework, several design challenges were completed. These case studies include the design and development of an active hinge for the deployment of a solar array or foldable space structure, an adaptive solar array deployment and positioning system, a passive air temperature controller for the regulation of flow temperatures inside of a jet engine, and a redesign of the Corvette active hatch, which allows for pressure equalization of the car interior. For each of the presented case studies, a prototype or proof-of-concept was fabricated and the experimental results and lessons learned are discussed. This analysis presents a collection of CASMART collaborative best practices in order to allow readers to utilize the available design tools and understand their modeling principles. These design tools, which are based on engineering models, can provide first-order optimal designs and are a basic and efficient method for either demonstrating design feasibility or refining design parameters. Although the design and integration of an SMA-based actuation system always requires application- and environment-specific engineering considerations, common modeling tools can significantly reduce the investment required for actuation system development and provide valuable engineering insight.

A Customer-Driven Approach to One-of-a-Kind Product Design

2007 ◽  
Author(s):  
Huijun Song ◽  
Deyi Xue ◽  
Yiliu Tu
Keyword(s):  
Product Design ◽  
Technical Level ◽  
Customer Requirements ◽  
Industrial Case Study ◽  
Product Families ◽  
Decomposition Approach ◽  
Function Decomposition ◽  
Optimal Product Design ◽  
Different Levels

This research addresses the issues to identify the optimal product design based on individual customer requirements in one-of-a-kind production (OKP). In this work, a function decomposition approach is introduced for modeling the variations of design functions, configurations, and parameters in generic OKP product families. Requirements of individual customers are modeled at two different levels: function level and technical level. Customized OKP products are created from the generic OKP product families based on customer requirements. The optimal product design is identified from feasible design candidates through optimization. An industrial case study is given to demonstrate the effectiveness of the introduced approach.

scholarly journals A Hierarchical Modeling and Analysis Framework for Availability and Security Quantification of IoT Infrastructures

Electronics ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 155 ◽  
Author(s):  
Tuan Anh Nguyen ◽  
Dugki Min ◽  
Eunmi Choi
Keyword(s):  
Virtual Machine ◽  
Hierarchical Model ◽  
Hierarchical Modeling ◽  
Smart Factory ◽  
Analysis Framework ◽  
Security Measures ◽  
Modeling Framework ◽  
System Architectures ◽  
Modeling And Analysis

Modeling a complete Internet of Things (IoT) infrastructure is crucial to assess its availability and security characteristics. However, modern IoT infrastructures often consist of a complex and heterogeneous architecture and thus taking into account both architecture and operative details of the IoT infrastructure in a monolithic model is a challenge for system practitioners and developers. In that regard, we propose a hierarchical modeling framework for the availability and security quantification of IoT infrastructures in this paper. The modeling methodology is based on a hierarchical model of three levels including (i) reliability block diagram (RBD) at the top level to capture the overall architecture of the IoT infrastructure, (ii) fault tree (FT) at the middle level to elaborate system architectures of the member systems in the IoT infrastructure, and (iii) continuous time Markov chain (CTMC) at the bottom level to capture detailed operative states and transitions of the bottom subsystems in the IoT infrastructure. We consider a specific case-study of IoT smart factory infrastructure to demonstrate the feasibility of the modeling framework. The IoT smart factory infrastructure is composed of integrated cloud, fog, and edge computing paradigms. A complete hierarchical model of RBD, FT, and CTMC is developed. A variety of availability and security measures are computed and analyzed. The investigation of the case-study’s analysis results shows that more frequent failures in cloud cause more severe decreases of overall availability, while faster recovery of edge enhances the availability of the IoT smart factory infrastructure. On the other hand, the analysis results of the case-study also reveal that cloud servers’ virtual machine monitor (VMM) and virtual machine (VM), and fog server’s operating system (OS) are the most vulnerable components to cyber-security attack intensity. The proposed modeling and analysis framework coupled with further investigation on the analysis results in this study help develop and operate the IoT infrastructure in order to gain the highest values of availability and security measures and to provide development guidelines in decision-making processes in practice.

Mode Switchover Strategy for Multi-port Energy Router Based on State Flow Diagram

2021 ◽  
Author(s):  
Jingwen Zheng ◽  
Zhiguo Wei ◽  
Zaixun Ling ◽  
Yu Guo ◽  
Ping Xiong ◽  
...  
Keyword(s):  
Flow Diagram ◽  
State Flow

Formal modeling and analysis of resource management for cloud architectures: an industrial case study using Real-Time ABS

2013 ◽  
Vol 8 (4) ◽  
pp. 323-339 ◽  
Author(s):  
Elvira Albert ◽  
Frank S. de Boer ◽  
Reiner Hähnle ◽  
Einar Broch Johnsen ◽  
Rudolf Schlatte ◽  
...  
Keyword(s):  
Resource Management ◽  
Real Time ◽  
Formal Modeling ◽  
Industrial Case Study ◽  
Modeling And Analysis

scholarly journals Explaining Gold-Mining and Non-Gold Mining Areas' Inequalities in Learning Achievements in Burkina Faso's Primary Education: A Decomposition Analysis

2021 ◽  
pp. 12-33
Author(s):  
Jean-Baptiste M. B. Sanfo ◽  
Keiichi Ogawa
Keyword(s):  
Burkina Faso ◽  
Primary Education ◽  
Influence Function ◽  
Gold Mining ◽  
Educational Inequality ◽  
Decomposition Analysis ◽  
School Factors ◽  
Student Background ◽  
Mining Areas ◽  
Function Decomposition

Research shows that learning achievements inequalities exist between students from gold mining areas and those from non-gold mining ones. However, there is no evidence on factors that explain this "new" geographic educational inequality. Exploiting the gold mining boom in Burkina Faso, this study employed re-centered influence function decomposition to explore students' background and school factors which explain these learning achievements inequalities and also estimate the proportion of inequalities explained by unmeasured factors. Findings suggest that, relative to student background factors, most of the learning achievements inequalities between the two types of areas are explained by school factors. Moreover, unmeasured educational factors explain a non-negligible proportion of the inequalities, higher for students on the lower and upper tails of the learning achievements distribution. Suggestions for policymakers are discussed based on the findings of the present study.

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