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6 results on '"Horikomi, Taizo"'

1. Generating In-store Customer Journeys from Scratch with GPT Architectures

Author

Horikomi, Taizo and Mizuno, Takayuki

Subjects
Computer Science - Machine Learning, Computer Science - Artificial Intelligence
Abstract

We propose a method that can generate customer trajectories and purchasing behaviors in retail stores simultaneously using Transformer-based deep learning structure. Utilizing customer trajectory data, layout diagrams, and retail scanner data obtained from a retail store, we trained a GPT-2 architecture from scratch to generate indoor trajectories and purchase actions. Additionally, we explored the effectiveness of fine-tuning the pre-trained model with data from another store. Results demonstrate that our method reproduces in-store trajectories and purchase behaviors more accurately than LSTM and SVM models, with fine-tuning significantly reducing the required training data.

Published
2024

2. Generating Individual Trajectories Using GPT-2 Trained from Scratch on Encoded Spatiotemporal Data

Author

Horikomi, Taizo, Fujimoto, Shouji, Ishikawa, Atushi, and Mizuno, Takayuki

Subjects
Computer Science - Machine Learning, Computer Science - Artificial Intelligence
Abstract

Following Mizuno, Fujimoto, and Ishikawa's research (Front. Phys. 2022), we transpose geographical coordinates expressed in latitude and longitude into distinctive location tokens that embody positions across varied spatial scales. We encapsulate an individual daily trajectory as a sequence of tokens by adding unique time interval tokens to the location tokens. Using the architecture of an autoregressive language model, GPT-2, this sequence of tokens is trained from scratch, allowing us to construct a deep learning model that sequentially generates an individual daily trajectory. Environmental factors such as meteorological conditions and individual attributes such as gender and age are symbolized by unique special tokens, and by training these tokens and trajectories on the GPT-2 architecture, we can generate trajectories that are influenced by both environmental factors and individual attributes.

Published
2023

5. Prevalence of Hepatitis A Immunity and Decision-tree Analysis Among Men Who Have Sex With Men and Are Living With Human Immunodeficiency Virus in Tokyo.

Author

Koibuchi, Tomohiko, Koga, Michiko, Kikuchi, Tadashi, Horikomi, Taizo, Kawamura, Yoshihiro, Lim, Lay Ahyoung, Adachi, Eisuke, Tsutsumi, Takeya, and Yotsuyanagi, Hiroshi

Subjects
AGE distribution, ALGORITHMS, DECISION trees, HEPATITIS A, HIV-positive persons, IMMUNITY, IMMUNIZATION, IMMUNOGLOBULINS, DISEASE prevalence, MEN who have sex with men
Abstract

Background Hepatitis A virus (HAV) can be sexually transmitted. However, the level of HAV immunity among patients living with human immunodeficiency virus (HIV) in Japan is unknown. Determining the epidemiology of HAV infections among men who have sex with men (MSM) and who are living with HIV is essential for an HAV vaccination program. This study examined HAV immunity in patients living with HIV and applied the decision-tree analysis to explore the factors of immunoglobulin G (IgG)-hepatitis A (HA) antibodies in MSM living with HIV. Methods We examined the presence of IgG-HA antibodies among patients living with HIV from January to December 2017 in The Hospital of The Institute of Medical Science, The University of Tokyo. We recorded each patient's age, sex, mode of HIV transmission, year of HIV diagnosis, HAV vaccine status, history of HAV infection, and history of other infectious diseases. A decision-tree algorithm was used to reveal the factors and profiles most relevant to the anti-HAV prevalence. Results Overall, 378 MSM patients living with HIV were examined for IgG-HA antibodies. After excluding 24 patients who had received a HAV vaccine, the data of 354 MSM were analyzed (median age 45 years, interquartile range 39–51 years). Of the 354 patients, 60 (16.9%) were positive for IgG-HA antibodies. The HA positivity rate increased with patients' age, and age (> 63.5 years) was extracted as the most important variable by classification of the decision-tree algorithm. Conclusions Our study, conducted just before the HAV outbreak among MSM in Tokyo, showed that age was the most relevant factor in anti-HAV prevalences. An extensive HAV vaccination program for MSM patients living with HIV is urgently needed, particularly for younger people. [ABSTRACT FROM AUTHOR]

Published
2020
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