A Statistical Approach to Causality Analysis in a Distributed Design Framework

Author(s):  
Jaehyun Kim ◽  
David Wallace

Numerous collaborative design tools have been developed to accelerate the product development, and recently environments for building distributed simulations have been proposed. For example, a simulation framework called DOME (Distributed Object-oriented Modeling and Evaluation) has been developed in MIT CADLAB. DOME is unique in its decentralized structure that allows heterogeneous simulations to be stitched together while allowing proprietary information an simulation models to remain secure with each participant. While such an approach offers many advantages, it also hides causality and sensitivity information, making it difficult for designers to understand problem structure and verify solutions. The purpose of this research is to analyze the relationships between design parameters (causality) and the strength of the relationships (sensitivity) in decentralized web-based design simulation. Algorithms and implementations for the causality and sensitivity analysis are introduced. Causality is determined using Granger’s definition of causality, which is to distinguish causation from association using conditional variance of the suspected output variable. Sensitivity is estimated by linear regression analysis and a perturbation method, which transfers the problem into a frequency domain by generating periodic perturbations. Varying Internet latency and disturbances are problematic issues with these methods. Thus, new algorithms are developed and tested to overcome these problems.

2007 ◽  
Vol 10-12 ◽  
pp. 220-224 ◽  
Author(s):  
Xiao Dai ◽  
Yi Qin ◽  
Neal P. Juster

A web-based collaborative design advisory system for designing micro products is being developed, which is based on use of both knowledge and rules. The system is aimed at helping designers to assess/optimise the design of micro products to be manufactured with micro-forming. The Microsoft C# programming language, ASP.Net technique and Microsoft Access database system have been used to develop this system. The system is composed of various assessment modules such as product geometry features, forming processes, materials, machines, tools and cost assessment modules. Clients can use/browse the user interface of the integrated system through the internet to import a CAD design model and define design parameters. The system is not only able to assess the client’s design but also to generate preliminary process plans for the selected micro-forming processes. A micro-pin design is used as an example to test the capability of the 1st prototype system. With such a system, some advantages such as increasing the design efficiency in the web-based collaborative design environment have been identified.


Author(s):  
Jun Yu ◽  
Zhenjun Ming ◽  
Guoxin Wang ◽  
Yan Yan ◽  
Xiaoping Lan

The development of complex product dynamic simulation models and the integration of design automation systems require knowledge from multiple heterogeneous data sources and tools. Because of the heterogeneity of model data, the integration of tools and data is a time-consuming and error-prone task. The main objective of this study is to provide a unified model of dynamic simulation for engineering design, which serves as a knowledge base to support the development of a dynamic simulation model. The integration of knowledge is realized through (i) definition of the structure and interface during the design phase of the dynamic simulation model, and (ii) definition of a model-driven integrated environment configuration process during the runtime phase. In order to achieve interoperability among the different simulation models in a collaborative design environment, we build a “Demand-Resources-Service-Knowledge-Process (DKRSP)” ontology that formally represents the semantics of dynamic simulation models. Based on the ontology, a knowledge base is created for the management of dynamic simulation knowledge. The efficacy of the ontology and the knowledge base are demonstrated using a transmission design example.


2021 ◽  
Vol 1 ◽  
pp. 731-740
Author(s):  
Giovanni Formentini ◽  
Claudio Favi ◽  
Claude Cuiller ◽  
Pierre-Eric Dereux ◽  
Francois Bouissiere ◽  
...  

AbstractOne of the most challenging activity in the engineering design process is the definition of a framework (model and parameters) for the characterization of specific processes such as installation and assembly. Aircraft system architectures are complex structures used to understand relation among elements (modules) inside an aircraft and its evaluation is one of the first activity since the conceptual design. The assessment of aircraft architectures, from the assembly perspective, requires parameter identification as well as the definition of the overall analysis framework (i.e., mathematical models, equations).The paper aims at the analysis of a mathematical framework (structure, equations and parameters) developed to assess the fit for assembly performances of aircraft system architectures by the mean of sensitivity analysis (One-Factor-At-Time method). The sensitivity analysis was performed on a complex engineering framework, i.e. the Conceptual Design for Assembly (CDfA) methodology, which is characterized by level, domains and attributes (parameters). A commercial aircraft cabin system was used as a case study to understand the use of different mathematical operators as well as the way to cluster attributes.


2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Patrícia Moura e Sá ◽  
Catarina Frade ◽  
Fernanda Jesus ◽  
Mónica Lopes ◽  
Teresa Maneca Lima ◽  
...  

PurposeWicked problems require collaborative innovation approaches. Understanding the problem from the users' perspective is essential. Based on a complex and ill-defined case, the purpose of the current paper is to identify some critical success factors in defining the “right problem” to be addressed.Design/methodology/approachAn empirical research study was carried out in a low-density municipality (case study). Extensive data were collected from official databases, individual semi-structured interviews and a focus group involving citizens, local authorities, civil servants and other relevant stakeholders.FindingsAs defined by the central government, the problem to be addressed by the research team was to identify which justice services should be made available locally to a small- and low-density community. The problem was initially formulated using top-down reasoning. In-depth contact with citizens and key local players revealed that the lack of justice services was not “the issue” for that community. Mobility constraints and the shortage of economic opportunities had a considerable impact on the lack of demand for justice services. By using a bottom-up perspective, it was possible to reframe the problem to be addressed and suggest a new concept to be tested at later stages.Social implicationsThe approach followed called attention to the importance of listening to citizens and local organisations with a profound knowledge of the territory to effectively identify and circumscribe a local problem in the justice field.Originality/valueThe paper highlights the limitations of traditional rational problem-solving approaches and contributes to expanding the voice-of-the-customer principle showing how it can lead to a substantially new definition of the problem to be addressed.


Author(s):  
Marian Sikora ◽  
Janusz Gołdasz

The aim of this work is to provide an insight into the rattle noise phenomena occurring in double-tube (twin-tube) vehicle suspension dampers. In the dampers the particular phenomenon results from interactions between the valve(s) and the fluid passing through them. The rattling noise phenomena is known to degrade the vehicle passenger’s perception of ride comfort as well as to influence the performance of the dampers at low and medium speeds in particular. In the paper the authors reveal the results of a DOE (Design of Experiment) study involving several design parameters known to affect rattling occurrence. By running a series of purpose-designed tests the authors investigate not only the contribution of each particular parameter but the interactions between them. The results are presented in the form of pareto charts, main effect plots as well as interaction plots. It is expected the outcome of the analysis will aid in a better comprehension of the phenomena as well the definition of valve configurations to minimize their performance degradation.


2005 ◽  
Vol 20 (2) ◽  
pp. 117-125 ◽  
Author(s):  
MICHAEL LUCK ◽  
EMANUELA MERELLI

The scope of the Technical Forum Group (TFG) on Agents in Bioinformatics (BIOAGENTS) was to inspire collaboration between the agent and bioinformatics communities with the aim of creating an opportunity to propose a different (agent-based) approach to the development of computational frameworks both for data analysis in bioinformatics and for system modelling in computational biology. During the day, the participants examined the future of research on agents in bioinformatics primarily through 12 invited talks selected to cover the most relevant topics. From the discussions, it became clear that there are many perspectives to the field, ranging from bio-conceptual languages for agent-based simulation, to the definition of bio-ontology-based declarative languages for use by information agents, and to the use of Grid agents, each of which requires further exploration. The interactions between participants encouraged the development of applications that describe a way of creating agent-based simulation models of biological systems, starting from an hypothesis and inferring new knowledge (or relations) by mining and analysing the huge amount of public biological data. In this report we summarize and reflect on the presentations and discussions.


2021 ◽  
Vol 2021 (6) ◽  
pp. 5366-5372
Author(s):  
MARIAN BOJKO ◽  
◽  
LUKAS HERTL ◽  
SYLVA DRABKOVA ◽  
◽  
...  

The twin-screw pump is designed for pumping highly viscous materials in the food industry. Rheological characteristics of materials are important in the specification of design parameters of screw pumps. Analysis of flow in the twin-screw pumps with definition of non-newtonian materials can be made by numerical modelling. CFD generally oriented software ANSYS Fluent and ANSYS Polyflow has been used for modelling. In this study those software’s (ANSYS Fluent and ANSYS Polyflow) were defined for solution of flow in the twin-screw pumps. Results were compared for the same boundary conditions on the inlet and outlet of the 3D model. For definition of the viscosity were used the Nonnewtonian power law. Parameters as consistency coefficient and flow exponent for Nonnewtonian power law were analysed by software ANSYS Fluent and ANSYS Polyflow. Postprocessing form ANSYS Fluent and ANSYS Polyflow were made by contours of field and by graphs.


2020 ◽  
Vol 4 (1) ◽  
Author(s):  
Brenda Le ◽  
Darren Tellier

In Canada, there is a growing interest in regulating the practices of acupuncture and Chinese herbology under the banner of ‘Traditional Chinese Medicine’ (TCM). However, the origins and definition of TCM are unclear and therefore disputed. While TCM is often used as an umbrella term to represent Chinese medical traditions that span millennia, numerous academics consider TCM to be a modern construct that has departed from the foundational roots of Chinese medicine. To better understand TCM and its implications for the profession, our study investigates: 1) historical precedents leading up to the formal creation of TCM; 2) characteristics and defining features of TCM; and 3) how this relates to education, practice and regulation of the profession in Canada. A mixed-methods study design was employed. Semi-structured interviews were conducted to explore perceptions of individuals who contributed to mediums that discussed the formation of TCM or traditions that exist outside of TCM. In addition, an anonymous web-based survey was sent to TCM-related professional organizations, who were asked to distribute the survey to their members to capture the views of persons practicing within TCM-related health professions in Canada. Due to a lack of participation from the organizations, no survey data was collected. Interviews revealed that TCM is a product of the standardization and simplification of Chinese medicine during the 1950’s and 60’s in China to meet healthcare needs at the time. Currently in Canada, there appears to be a lack of awareness that the establishment of TCM is not a comprehensive representation of Chinese medical traditions, and that many aspects of it may not be suited to the healthcare landscape of modern-day Canada. There is a need for more discussion surrounding the identity of this new profession.


2019 ◽  
Vol 5 (1) ◽  
pp. 26-35
Author(s):  
Hamed Vaezi ◽  
Hossein Karimi Moonaghi ◽  
Reyhaneh Golbaf

In recent years medical education has developed dramatically, but lecturers often cite the existence of a gap between theoretical and practical knowledge. In the first decade of the present century, new research methodology named “design-based research (DBR)” was developed, which most experts and journals refer to as a fundamental way to make changes in the quality and applicability of studies and educational research as well as to enhance and improve the practice of instruction. The aim of the present study was introducing design-based research and its concepts, features, applications, and challenges. A narrative review was conducted in 2018. For this purpose, authorized English academic database including Web of Science, Science Direct, Google Scholar, international database and library in medical research filed with keywords including “design-based research, definition of DBR, DBR applications, medical education, and DBR challenges” without date limitation until 2018.11.21 were screened. Overall, 68 articles were selected and after careful reading, 21 article with related subjects were selected for material extraction. The conclusion was made that DBR that combines empirical research with design-based theories could be considered as an effective method for understanding quality, time and the cause of the phenomenon of educational innovation in practice. Usually DBR is formed by initial evaluation of a problem that occurs in a particular context, and this assessment continues throughout design and implementation. One of the characteristics of DBR is the guiding team, which includes researchers, professionals, designers, managers, teachers, trainers and others whose expertise and knowledge may in some way help. The application of DBR in web-based training programs is quite evident. The probability of non-returns in short-term projects is one of the main challenges of DBR. Medical education has developed dramatically in recent years, but it has made little progress in promoting innovative research methodologies. DBR can be used as a bridge between theories and practice and provide the basis for close communication between researchers, designers, and participants. By applying sophisticated methods and multiple sources of information, the success rate of an intervention in a particular environment is assessed, which ultimately leads to improved theories.


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