Dimitri Mavris

Prof. Dr. Dimitri Mavris

S.P. Langley NIA Distinguished Regents Professor, Director of the Aerospace Systems Design Laboratory, School of Aerospace Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0150, USA
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Research Focus & Metrics

Academic Career Length

31Years (1996-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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28 September 2020 in Aerospace
Verified
Journal Article
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RRRodrigo Rose
Rodrigo Rose
Tejas PuranikTejas Puranik
Tejas Puranik
Dimitri MavrisDimitri Mavris
Dimitri Mavris
The complexity of commercial aviation operations has grown substantially in recent years, together with a diversification of techniques for collecting and analyzing flight data. As a result, data-driven frameworks for enhancing flight safety have grown in popularity. Data-driven techniques offer efficient and repeatable exploration of patterns and anomalies in large datasets. Text-based flight safety data presents a unique challenge in its subjectivity, and relies on natural language processing tools to extract underlying trends from narratives. In this paper, a methodology is presented for the analysis of aviation safety narratives based on text-based accounts of in-flight events and categorical metadata parameters which accompany them. An extensive pre-processing routine is presented, including a comparison between numeric models of textual representation for the purposes of document classification. A framework for categorizing and visualizing narratives is presented through a combination of k-means clustering and 2-D mapping with t-Distributed Stochastic Neighbor Embedding (t-SNE). A cluster post-processing routine is developed for identifying driving factors in each cluster and building a hierarchical structure of cluster and sub-cluster labels. The Aviation Safety Reporting System (ASRS), which includes over a million de-identified voluntarily submitted reports describing aviation safety incidents for commercial flights, is analyzed as a case study for the methodology. The method results in the identification of 10 major clusters and a total of 31 sub-clusters. The identified groupings are post-processed through metadata-based statistical analysis of the learned clusters. The developed method shows promise in uncovering trends from clusters that are not evident in existing anomaly labels in the data and offers a new tool for obtaining insights from text-based safety data that complement existing approaches.

11 March 2023 in Aerospace
Verified
Journal Article
Open access
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Archana Tikayat RayArchana Tikayat Ray
Archana Tikayat Ray
BCBjorn F. Cole
Bjorn F. Cole
Olivia Pinon FischerOlivia Pinon Fischer
Olivia Pinon Fischer
RWRyan White
Ryan White
Dimitri MavrisDimitri Mavris
Dimitri Mavris
The system complexity that characterizes current systems warrants an integrated and comprehensive approach to system design and development. This need has brought about a paradigm shift towards Model-Based Systems Engineering (MBSE) approaches to system design and a departure from traditional document-centric methods. While MBSE shows great promise, the ambiguities and inconsistencies present in Natural Language (NL) requirements hinder their conversion to models directly. The field of Natural Language Processing (NLP) has demonstrated great potential in facilitating the conversion of NL requirements into a semi-machine-readable format that enables their standardization and use in a model-based environment. A first step towards standardizing requirements consists of classifying them according to the type (design, functional, performance, etc.) they represent. To that end, a language model capable of classifying requirements needs to be fine-tuned on labeled aerospace requirements. This paper presents an open-source, annotated aerospace requirements corpus (the first of its kind) developed for the purpose of this effort that includes three types of requirements, namely design, functional, and performance requirements. This paper further describes the use of the aforementioned corpus to fine-tune BERT to obtain the aeroBERT-Classifier: a new language model for classifying aerospace requirements into design, functional, or performance requirements. Finally, this paper provides a comparison between aeroBERT-Classifier and other text classification models such as GPT-2, Bidirectional Long Short-Term Memory (Bi-LSTM), and bart-large-mnli. In particular, it shows the superior performance of aeroBERT-Classifier on classifying aerospace requirements over existing models, and this is despite the fact that the model was fine-tuned using a small labeled dataset.

4 June 2020 in Aerospace
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Journal Article
Open access
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HLHyunKi Lee
HyunKi Lee
Sasha MadarSasha Madar
Sasha Madar
Santusht SairamSantusht Sairam
Santusht Sairam
Tejas PuranikTejas Puranik
Tejas Puranik
APAlexia Payan
Alexia Payan
Dimitri MavrisDimitri Mavris
Dimitri Mavris
In recent years, there has been a rapid growth in the application of data science techniques that leverage aviation data collected from commercial airline operations to improve safety. This paper presents the application of machine learning to improve the understanding of risk factors during flight and their causal chains. With increasing complexity and volume of operations, rapid accumulation and analysis of this safety-related data has the potential to maintain and even lower the low global accident rates in aviation. This paper presents the development of an analytical methodology called Safety Analysis of Flight Events (SAFE) that synthesizes data cleaning, correlation analysis, classification-based supervised learning, and data visualization schema to streamline the isolation of critical parameters and the elimination of tangential factors for safety events in aviation. The SAFE methodology outlines a robust and repeatable framework that is applicable across heterogeneous data sets containing multiple aircraft, airport of operations, and phases of flight. It is demonstrated on Flight Operations Quality Assurance (FOQA) data from a commercial airline through use cases related to three safety events, namely Tire Speed Event, Roll Event, and Landing Distance Event. The application of the SAFE methodology yields a ranked list of critical parameters in line with subject-matter expert conceptions of these events for all three use cases. The work concludes by raising important issues about the compatibility levels of machine learning and human conceptualization of incidents and their precursors, and provides initial guidance for their reconciliation.

31 August 2023 in Aerospace
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Journal Article
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Archana Tikayat RayArchana Tikayat Ray
Archana Tikayat Ray
ABAnirudh Prabhakara Bhat
Anirudh Prabhakara Bhat
RWRyan White
Ryan White
VNVan Minh Nguyen
Van Minh Nguyen
Olivia Pinon FischerOlivia Pinon Fischer
Olivia Pinon Fischer
Dimitri MavrisDimitri Mavris
Dimitri Mavris
This research investigates the potential application of generative language models, especially ChatGPT, in aviation safety analysis as a means to enhance the efficiency of safety analyses and accelerate the time it takes to process incident reports. In particular, ChatGPT was leveraged to generate incident synopses from narratives, which were subsequently compared with ground-truth synopses from the Aviation Safety Reporting System (ASRS) dataset. The comparison was facilitated by using embeddings from Large Language Models (LLMs), with aeroBERT demonstrating the highest similarity due to its aerospace-specific fine-tuning. A positive correlation was observed between the synopsis length and its cosine similarity. In a subsequent phase, human factors issues involved in incidents, as identified by ChatGPT, were compared to human factors issues identified by safety analysts. The precision was found to be 0.61, with ChatGPT demonstrating a cautious approach toward attributing human factors issues. Finally, the model was utilized to execute an evaluation of accountability. As no dedicated ground-truth column existed for this task, a manual evaluation was conducted to compare the quality of outputs provided by ChatGPT to the ground truths provided by safety analysts. This study discusses the advantages and pitfalls of generative language models in the context of aviation safety analysis and proposes a human-in-the-loop system to ensure responsible and effective utilization of such models, leading to continuous improvement and fostering a collaborative approach in the aviation safety domain.

1 December 2017 in Robotics and Autonomous Systems
Verified
Journal Article
Closed access
YCYoungjun Choi
Youngjun Choi
HJHernando Jimenez
Hernando Jimenez
Dimitri MavrisDimitri Mavris
Dimitri Mavris

25 November 2022 in Aerospace
Verified
Journal Article
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ZGZhenyu Gao
Zhenyu Gao
Dimitri MavrisDimitri Mavris
Dimitri Mavris
The rapid growth of global aviation operations has made its negative environmental impact an international concern. Accurate modeling of aircraft fuel burn, emissions, and noise is the prerequisite for informing new operational procedures, technologies, and policies towards a more sustainable future of aviation. In the past decade, due to the advances in big data technologies and effective algorithms, the transformative data-driven analysis has begun to play a substantial role in aviation environmental impact analysis. The integration of statistical and machine learning methods in the workflow has made such analysis more efficient and accurate. Through summarizing and classifying the representative works in this intersection area, this survey paper aims to extract prevailing research trends and suggest research opportunities for the future. The methodology overview section presents a comprehensive development process and landscape of statistical and machine learning methods for applied researchers. In the main section, relevant works in the literature are organized into seven application themes: data reduction, efficient computation, predictive modeling, uncertainty quantification, pattern discovery, verification and validation, and infrastructure and tools. Each theme contains background information, in-depth discussion, and a summary of representative works. The paper concludes with the proposal of five future opportunities for this research area.