Leandro Okimoto

Dr. Leandro Okimoto

orcid

Research Focus & Metrics

Academic Career Length

5Years (2022-Present)

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

Representative Publications

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6 February 2025 in Preprints.org
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Preprint
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GAGustavo de Aquino e Aquino Aquino
Gustavo de Aquino e Aquino Aquino
NANádila Silva Azevedo
Nádila Silva Azevedo
LOLeandro Okimoto
Leandro Okimoto
LCLeonardo Yuto Suzuki Camelo
Leonardo Yuto Suzuki Camelo
HBHendrio Bragança
Hendrio Bragança
Israel Gondres TornéIsrael Gondres Torné
Israel Gondres Torné
The rapid evolution of intelligent chatbots has been largely driven by the advent of Large Language Models (LLMs), which have greatly enhanced natural language understanding and generation. However, the fast-paced advancements in generative Artificial Intelligence (AI) and LLM technologies present challenges for developers to stay up-to-date and to select optimal architectures or approaches from a wide range of available options. This survey article addresses these challenges by providing a overview of cutting-edge techniques and architectural application choices in modern generative chatbot development. We explore various approaches involving retrieval strategies, chunking methods, context management, embeddings, and the utilization of LLMs. Furthermore, we analyze paradigms such as naive Retrieval-Augmented Generation (RAG) compared to Graph-Based RAG, as well as single-agent versus multi-agent systems. We examine agent-based methodologies, comparing single-agent systems with multi-agent architectures, and analyze how multi-agent systems can proficiently handle intricate tasks, enhance scalability, and mitigate faults such as hallucinations through collaborative efforts. Additionally, we review tools and frameworks such as LangGraph that facilitate the implementation of stateful, multi-agent LLM applications. By categorizing and analyzing these modern techniques, this survey aims to present the current landscape and future directions in chatbot development.

1 March 2024 in BMC Bioinformatics
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Journal Article
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LOLeandro Okimoto
Leandro Okimoto
RMRayol Mendonca-Neto
Rayol Mendonca-Neto
FNFabíola G. Nakamura
Fabíola G. Nakamura
ENEduardo F. Nakamura
Eduardo F. Nakamura
DFDavid Fenyö
David Fenyö
CSClaudio T. Silva
Claudio T. Silva
Background: In recent years, researchers have made significant strides in understanding the heterogeneity of breast cancer and its various subtypes. However, the wealth of genomic and proteomic data available today necessitates efficient frameworks, instruments, and computational tools for meaningful analysis. Despite its success as a prognostic tool, the PAM50 gene signature’s reliance on many genes presents challenges in terms of cost and complexity. Consequently, there is a need for more efficient methods to classify breast cancer subtypes using a reduced gene set accurately. Results: This study explores the potential of achieving precise breast cancer subtype categorization using a reduced gene set derived from the PAM50 gene signature. By employing a “Few-Shot Genes Selection” method, we randomly select smaller subsets from PAM50 and evaluate their performance using metrics and a linear model, specifically the Support Vector Machine (SVM) classifier. In addition, we aim to assess whether a more compact gene set can maintain performance while simplifying the classification process. Our findings demonstrate that certain reduced gene subsets can perform comparable or superior to the full PAM50 gene signature. Conclusions: The identified gene subsets, with 36 genes, have the potential to contribute to the development of more cost-effective and streamlined diagnostic tools in breast cancer research and clinical settings.

22 September 2022 in Journal of the Brazilian Computer Society
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Journal Article
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RMRayol Mendonca-Neto
Rayol Mendonca-Neto
JRJoão Reis
João Reis
LOLeandro Okimoto
Leandro Okimoto
David FenyoDavid Fenyo
David Fenyo
CSClaudio Silva
Claudio Silva
ENEduardo Nakamura
Eduardo Nakamura
Breast cancer is the second most common cancer type and is the leading cause of cancer-related deaths worldwide. Since it is a heterogeneous disease, subtyping breast cancer plays an important role in performing a specific treatment. In this work, we propose an evaluation framework that uses different machine learning techniques for a broader analysis of the PAM50 list in the classification of breast cancer subtypes. The experiments show that the best method to be used in the classification of breast cancer subtypes is the SVM with linear kernel, which presented an F1 score of 0.98 for the Basal subtype and 0.90 for the Her 2 subtype, the two subtypes with worse prognosis, respectively. We also presented a gene analysis for the classification methods using SHAP values, where we found which genes are important for the classification of each subtype.

24 August 2024 in Data in Brief
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Journal Article
Open access
HSHeitor Lifsitch Nogueira da Silva
Heitor Lifsitch Nogueira da Silva
GRGabriel Rocha
Gabriel Rocha
HBHendrio Bragança
Hendrio Bragança
CFCláudio Filho
Cláudio Filho
LOLeandro Okimoto
Leandro Okimoto
FCFábio Cardoso
Fábio Cardoso
To enhance the field of continuous motor health monitoring, we present FAN-COIL-I, an extensive vibration sensor dataset derived from a Fan Coil motor. This dataset is uniquely positioned to facilitate the detection and prediction of motor health issues, enabling a more efficient maintenance scheduling process that can potentially obviate the need for regular checks. Unlike existing datasets, often created under controlled conditions or through simulations, FAN-COIL-I is compiled from real-world operational data, providing an invaluable resource for authentic motor diagnosis and predictive maintenance research. Gathered using a high-resolution 32 KHz sampling rate, the dataset encompasses comprehensive vibration readings from both the forward and rear sides of the Fan Coil motor over a continuous two-week period, offering a rare glimpse into the dynamic operational patterns of these systems in a corporate setting. FAN-COIL-I stands out not only for its real-world applicability but also for its potential to serve as a reliable benchmark for researchers and practitioners seeking to validate their models against genuine engine conditions. (c) 2024 The Author(s). Published by Elsevier Inc. This is an open access article under the CC BY license ( http://creativecommons.org/licenses/by/4.0/ )