30 research outputs found

    Development of FRAM Model Based on Structure of Complex Adaptive Systems to Visualize Safety of Socio-Technical Systems

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    FRAM: Functional Resonance Analysis Method is an effective way to know about the safety of complex Socio-Technical Systems. However, it is a method rather than model and required to be extended for its practical usage. According to this, in this paper, a latest version of FRAM simulator based on our developed model is presented. The model simulates a process in which variabilities exiting in a working environment induce variability of FRAM functions that emerge out of the dynamic interactions among the functions as well as with the environment. Moreover, the model simulates a process where a specific context composed of variabilities existing in a working environment "shakes" FRAM functions, while the context is "shaken" by those functions vice versa, which is a typical dynamics specific to complex adaptive systems. This is implemented by integrating FRAM and Fuzzy CREAM which is an extended model of CREAM: Cognitive Reliability and Error Analysis Method with fuzzy reasoning. It enables to parameterize the variabilities, define the context, and formulate their interactions quantitatively, whose result is given as a dynamical change of state in each FRAM function

    Counterfactual inference to predict causal knowledge graph for relational transfer learning by assimilating expert knowledge --Relational feature transfer learning algorithm

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    Transfer learning (TL) is a machine learning (ML) method in which knowledge is transferred from the existing models of related problems to the model for solving the problem at hand. Relational TL enables the ML models to transfer the relationship networks from one domain to another. However, it has two critical issues. One is determining the proper way of extracting and expressing relationships among data features in the source domain such that the relationships can be transferred to the target domain. The other is how to do the transfer procedure. Knowledge graphs (KGs) are knowledge bases that use data and logic to graph-structured information; they are helpful tools for dealing with the first issue. The proposed relational feature transfer learning algorithm (RF-TL) embodies an extended structural equation modelling (SEM) as a method for constructing KGs. Additionally, in fields such as medicine, economics, and law related to people’s lives and property safety and security, the knowledge of domain experts is a gold standard. This paper introduces the causal analysis and counterfactual inference in the TL domain that directs the transfer procedure. Different from traditional feature-based TL algorithms like transfer component analysis (TCA) and CORelation Alignment (CORAL), RF-TL not only considers relations between feature items but also utilizes causality knowledge, enabling it to perform well in practical cases. The algorithm was tested on two different healthcare-related datasets — sleep apnea questionnaire study data and COVID-19 case data on ICU admission — and compared its performance with TCA and CORAL. The experimental results show that RF-TL can generate better transferred models that give more accurate predictions with fewer input features

    Comparing eye-tracking metrics of mental workload caused by NDRTs in semi-autonomous driving

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    The objective of this study was to verify the effectiveness of eye-tacking metrics in indicating driver’s mental workload in semi-autonomous driving when the driver is engaged in different non-driving related tasks (NDRTs). A driving simulator was developed for three scenarios (high-, medium-, and low-mental workload presented by SAE (Society of Automotive Engineers) Levels 0, 1, and 2) and three uni-modality secondary tasks. Thirty-six individuals participated in the driving simulation experiment. NASA-TLX (Task Load Index), secondary task performance, and eye-tracking metrics were used as indicators of mental workload. The subjective rating using the NASA-TLX showed a main effect of autonomous level on mental workload in both visual and auditory tasks. Correlation-matrix calculation and principal-component extraction indicated that pupil diameter change, number of saccades, saccade duration, fixation duration, and 3D gaze entropy were effective indicators of a driver’s mental workload in the visual and auditory multi-tasking situations of semi-autonomous driving. The accuracy of predicting the mental-workload level using the K-Nearest Neighbor (KNN) classifier was 88.9% with bootstrapped data. These results can be used to develop an adaptive multi-modal interface that issues efficient and safe takeover requests

    Adaptive multi-modal interface model concerning mental workload in take-over request during semi-autonomous driving

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    With the development of automated driving technologies, human factors involved in automated driving are gaining increasing attention for a balanced implementation of the convenience brought by the technology and safety risk in commercial vehicle models. One influential human factor is mental workload. In the take-over request (TOR) from autonomous to manual driving at level 3 of International Society of Automotive Engineers' (SAE) Levels of Driving Automation, the time window for the driver to have full comprehension of the driving environment is extremely short, which means the driver is under high mental workload. To support the driver during a TOR, we propose an adaptive multi-modal interface model concerning mental workload. In this study, we evaluated the reliability of only part of the proposed model in a driving-simulator experiment as well as using the experimental data from a previous study

    Introduce structural equation modelling to machine learning problems for building an explainable and persuasive model

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    With the development of artificial intelligence technologies, the high accuracy of machine learning methods has become a non-unique standard. People are beginning to be more concerned about the understandability between humans and machines. The interference procedure of the machines is hoped to accord with human thinking as much as possible, which has spawned the recent and ongoing demands for developing explainable models. The present study proposes a new explainable and persuasive model for machine learning problems by introducing Structural Equation Modelling into the picture. Six parts make up the model, from data collection to model evaluation. The model can be used for data analysis, machine learning, and causal analysis. The proposed model is also transparent and can be interpreted from design to application. A practical experiment shows its effectiveness in a healthcare problem

    Assimilation and Accommodation for Self-organizational Learning of Autonomous Robots

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    Abstract In this paper, we propose a new self-organizational machine learning system, called Dual-Schemata model. This model is based on Piaget's schema theory, which is well known theory in developmental psychology. In our model, we divide Piaget's original schema into two parts; one is a perceptional schema and the other is an intentional schema. By this division, we can describe both adaptation and learning processes of a human and/or of an autonomous robot more simply and more effectively. Further, we show a series of experiments, in which a facial-robot with our Dual-Schemata model attempts to chase movements of a colored ball, and then we present that a robot gets to obtain some inner symbols concerning with those ball movements

    階層型因果知識構造に基づく知的意思決定支援システム

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    京都大学0048新制・課程博士工学博士甲第3890号工博第990号新制||工||709(附属図書館)UT51-63-C108京都大学大学院工学研究科精密工学専攻(主査)教授 岩井 壯介, 教授 人見 勝人, 教授 片山 徹学位規則第5条第1項該当Kyoto UniversityDFA

    Extended FRAM model based on cellular automaton to clarify complexity of socio-technical systems and improve their safety

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    The safety of socio-technical systems is intractable by traditional approaches, such as a simple cause-effect analysis. It would be no longer effective only to eliminate potential hazards or to explain why things go wrong (i.e., the limitation of the approach called Safety-I). The safety instead could be improved by validating why everyday operations go right and by verifying their resilience, based on an alternative idea of Safety-II. The objective of this research is to develop a tool enabling us to validate and verifying safeties based on the functional resonance analysis method (FRAM). FRAM would be an effective way to analyze the safety of complex socio-technical systems. However, FRAM only provides a conceptual methodology, and further extensions and implementations are needed. This work first presents an extended FRAM model based on a classical idea of cellular automaton, and the result of applying our model to a steel production management problem is provided. Steel production line reveals a quite complicated process consisting of many linked workstations where a production flow might be varied frequently. Wherein flexible delivery decisions are required, including changing the supply chains themselves. There exists empirical know-how to tackle those, but these remain as tacit knowledge, and there has been no way to validate and verify their effectiveness under specific conditions. The results of applying our extended FRAM model to this example provide several insights concerning the characteristics of experienced workers’ operations to handle and manage the process’s complexities, such as harnessing, phase transformation, and identifying critical points attaining resilient operations in terms of the entropy of the process status. We also discuss how these findings contribute to the safety management of the other socio-technical systems based on the findings of the analysis
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