Search

Your search keyword '"Choi, Yong-Hoon"' showing total 227 results
Start Over Author "Choi, Yong-Hoon"
227 results on '"Choi, Yong-Hoon"'

1. Synergistic Formulaic Alpha Generation for Quantitative Trading based on Reinforcement Learning

Author

Shin, Hong-Gi, Jeong, Sukhyun, Kim, Eui-Yeon, Hong, Sungho, Cho, Young-Jin, and Choi, Yong-Hoon

Subjects
Computer Science - Computational Engineering, Finance, and Science, Computer Science - Artificial Intelligence
Abstract

Mining of formulaic alpha factors refers to the process of discovering and developing specific factors or indicators (referred to as alpha factors) for quantitative trading in stock market. To efficiently discover alpha factors in vast search space, reinforcement learning (RL) is commonly employed. This paper proposes a method to enhance existing alpha factor mining approaches by expanding a search space and utilizing pretrained formulaic alpha set as initial seed values to generate synergistic formulaic alpha. We employ information coefficient (IC) and rank information coefficient (Rank IC) as performance evaluation metrics for the model. Using CSI300 market data, we conducted real investment simulations and observed significant performance improvement compared to existing techniques., Comment: Accepted by ICOIN 2024

Published
2024

2. Adversarial Training of Denoising Diffusion Model Using Dual Discriminators for High-Fidelity Multi-Speaker TTS

Author

Ko, Myeongjin and Choi, Yong-Hoon

Subjects
Computer Science - Sound, Computer Science - Machine Learning, Electrical Engineering and Systems Science - Audio and Speech Processing
Abstract

The diffusion model is capable of generating high-quality data through a probabilistic approach. However, it suffers from the drawback of slow generation speed due to the requirement of a large number of time steps. To address this limitation, recent models such as denoising diffusion implicit models (DDIM) focus on generating samples without directly modeling the probability distribution, while models like denoising diffusion generative adversarial networks (GAN) combine diffusion processes with GANs. In the field of speech synthesis, a recent diffusion speech synthesis model called DiffGAN-TTS, utilizing the structure of GANs, has been introduced and demonstrates superior performance in both speech quality and generation speed. In this paper, to further enhance the performance of DiffGAN-TTS, we propose a speech synthesis model with two discriminators: a diffusion discriminator for learning the distribution of the reverse process and a spectrogram discriminator for learning the distribution of the generated data. Objective metrics such as structural similarity index measure (SSIM), mel-cepstral distortion (MCD), F0 root mean squared error (F0 RMSE), short-time objective intelligibility (STOI), perceptual evaluation of speech quality (PESQ), as well as subjective metrics like mean opinion score (MOS), are used to evaluate the performance of the proposed model. The evaluation results show that the proposed model outperforms recent state-of-the-art models such as FastSpeech2 and DiffGAN-TTS in various metrics. Our implementation and audio samples are located on GitHub.

Published
2023
Full Text
View/download PDF

3. SC VALL-E: Style-Controllable Zero-Shot Text to Speech Synthesizer

Author

Kim, Daegyeom, Hong, Seongho, and Choi, Yong-Hoon

Subjects
Computer Science - Sound, Computer Science - Machine Learning, Electrical Engineering and Systems Science - Audio and Speech Processing
Abstract

Expressive speech synthesis models are trained by adding corpora with diverse speakers, various emotions, and different speaking styles to the dataset, in order to control various characteristics of speech and generate the desired voice. In this paper, we propose a style control (SC) VALL-E model based on the neural codec language model (called VALL-E), which follows the structure of the generative pretrained transformer 3 (GPT-3). The proposed SC VALL-E takes input from text sentences and prompt audio and is designed to generate controllable speech by not simply mimicking the characteristics of the prompt audio but by controlling the attributes to produce diverse voices. We identify tokens in the style embedding matrix of the newly designed style network that represent attributes such as emotion, speaking rate, pitch, and voice intensity, and design a model that can control these attributes. To evaluate the performance of SC VALL-E, we conduct comparative experiments with three representative expressive speech synthesis models: global style token (GST) Tacotron2, variational autoencoder (VAE) Tacotron2, and original VALL-E. We measure word error rate (WER), F0 voiced error (FVE), and F0 gross pitch error (F0GPE) as evaluation metrics to assess the accuracy of generated sentences. For comparing the quality of synthesized speech, we measure comparative mean option score (CMOS) and similarity mean option score (SMOS). To evaluate the style control ability of the generated speech, we observe the changes in F0 and mel-spectrogram by modifying the trained tokens. When using prompt audio that is not present in the training data, SC VALL-E generates a variety of expressive sounds and demonstrates competitive performance compared to the existing models. Our implementation, pretrained models, and audio samples are located on GitHub.

Published
2023

4. Optimal Cyber Attack Strategy Using Reinforcement Learning Based on Common Vulnerability Scoring System.

Author

Kim, Bum-Sok, Suk, Hye-Won, Choi, Yong-Hoon, Moon, Dae-Sung, and Kim, Min-Suk

Subjects
REINFORCEMENT learning, CYBERTERRORISM, ARTIFICIAL intelligence, DATA security failures, SECURITY systems
Abstract

Currently, cybersecurity threats such as data breaches and phishing have been on the rise due to the many different attack strategies of cyber attackers, significantly increasing risks to individuals and organizations. Traditional security technologies such as intrusion detection have been developed to respond to these cyber threats. Recently, advanced integrated cybersecurity that incorporates Artificial Intelligence has been the focus. In this paper, we propose a response strategy using a reinforcement-learning-based cyber-attack-defense simulation tool to address continuously evolving cyber threats. Additionally, we have implemented an effective reinforcement-learning-based cyber-attack scenario using Cyber Battle Simulation, which is a cyber-attack-defense simulator. This scenario involves important security components such as node value, cost, firewalls, and services. Furthermore, we applied a new vulnerability assessment method based on the Common Vulnerability Scoring System. This approach can design an optimal attack strategy by considering the importance of attack goals, which helps in developing more effective response strategies. These attack strategies are evaluated by comparing their performance using a variety of Reinforcement Learning methods. The experimental results show that RL models demonstrate improved learning performance with the proposed attack strategy compared to the original strategies. In particular, the success rate of the Advantage Actor-Critic-based attack strategy improved by 5.04 percentage points, reaching 10.17%, which represents an impressive 98.24% increase over the original scenario. Consequently, the proposed method can enhance security and risk management capabilities in cyber environments, improving the efficiency of security management and significantly contributing to the development of security systems. [ABSTRACT FROM AUTHOR]

Published
2024
Full Text
View/download PDF

21. IP Mobility Performance Enhancement Using Link-Layer Prediction

Author

Lee, Jun-Hui, Kim, Hyun-Woo, Choi, Yong-Hoon, Chung, Young-Uk, Rhee, Seung-Hyong, Hutchison, David, Series editor, Kanade, Takeo, Series editor, Kittler, Josef, Series editor, Kleinberg, Jon M., Series editor, Mattern, Friedemann, Series editor, Mitchell, John C., Series editor, Naor, Moni, Series editor, Nierstrasz, Oscar, Series editor, Pandu Rangan, C., Series editor, Steffen, Bernhard, Series editor, Sudan, Madhu, Series editor, Terzopoulos, Demetri, Series editor, Tygar, Doug, Series editor, Vardi, Moshe Y., Series editor, Weikum, Gerhard, Series editor, Kim, Tai-hoon, editor, Lee, Young-hoon, editor, Kang, Byeong-Ho, editor, and Ślęzak, Dominik, editor

Published
2010
Full Text
View/download PDF

22. Energy Efficient Coexistence of WiFi and WiMAX Systems Sharing Frequency Band

Author

Kim, Jongwoo, Park, Suwon, Rhee, Seung Hyong, Choi, Yong-Hoon, Hwang, HoYoung, Hutchison, David, Series editor, Kanade, Takeo, Series editor, Kittler, Josef, Series editor, Kleinberg, Jon M., Series editor, Mattern, Friedemann, Series editor, Mitchell, John C., Series editor, Naor, Moni, Series editor, Nierstrasz, Oscar, Series editor, Pandu Rangan, C., Series editor, Steffen, Bernhard, Series editor, Sudan, Madhu, Series editor, Terzopoulos, Demetri, Series editor, Tygar, Doug, Series editor, Vardi, Moshe Y., Series editor, Weikum, Gerhard, Series editor, Kim, Tai-hoon, editor, Lee, Young-hoon, editor, Kang, Byeong-Ho, editor, and Ślęzak, Dominik, editor

Published
2010
Full Text
View/download PDF

24. A Joint MAC Discovery-Routing Protocol for Self-Organizing Hierarchical Ad Hoc Networks

Author

Lee, Hyukjoon, Choi, Yong-Hoon, Chung, Young-uk, Yang, Seomin, Hutchison, David, editor, Kanade, Takeo, editor, Kittler, Josef, editor, Kleinberg, Jon M., editor, Mattern, Friedemann, editor, Mitchell, John C., editor, Naor, Moni, editor, Nierstrasz, Oscar, editor, Pandu Rangan, C., editor, Steffen, Bernhard, editor, Sudan, Madhu, editor, Terzopoulos, Demetri, editor, Tygar, Dough, editor, Vardi, Moshe Y., editor, Weikum, Gerhard, editor, Min, Geyong, editor, Di Martino, Beniamino, editor, Yang, Laurence T., editor, Guo, Minyi, editor, and Rünger, Gudula, editor

Published
2006
Full Text
View/download PDF

25. Power Saving Mechanisms of IEEE 802.16e: Sleep Mode vs. Idle Mode

Author

Kim, Beomjoon, Park, Jaesung, Choi, Yong-Hoon, Hutchison, David, editor, Kanade, Takeo, editor, Kittler, Josef, editor, Kleinberg, Jon M., editor, Mattern, Friedemann, editor, Mitchell, John C., editor, Naor, Moni, editor, Nierstrasz, Oscar, editor, Pandu Rangan, C., editor, Steffen, Bernhard, editor, Sudan, Madhu, editor, Terzopoulos, Demetri, editor, Tygar, Dough, editor, Vardi, Moshe Y., editor, Weikum, Gerhard, editor, Min, Geyong, editor, Di Martino, Beniamino, editor, Yang, Laurence T., editor, Guo, Minyi, editor, and Rünger, Gudula, editor

Published
2006
Full Text
View/download PDF

26. Performance Analysis of Group Handoff in Multihop Mesh Relay System

Author

Chung, Young-uk, Choi, Yong-Hoon, Lee, Hyukjoon, Hutchison, David, editor, Kanade, Takeo, editor, Kittler, Josef, editor, Kleinberg, Jon M., editor, Mattern, Friedemann, editor, Mitchell, John C., editor, Naor, Moni, editor, Nierstrasz, Oscar, editor, Pandu Rangan, C., editor, Steffen, Bernhard, editor, Sudan, Madhu, editor, Terzopoulos, Demetri, editor, Tygar, Dough, editor, Vardi, Moshe Y., editor, Weikum, Gerhard, editor, Kim, Young-Tak, editor, and Takano, Makoto, editor

Published
2006
Full Text
View/download PDF

27. A Network Management Approach for QoS Evaluation of IP Multimedia Services

Author

Choi, Yong-Hoon, Kim, Beomjoon, Park, Jaesung, Hutchison, David, editor, Kanade, Takeo, editor, Kittler, Josef, editor, Kleinberg, Jon M., editor, Mattern, Friedemann, editor, Mitchell, John C., editor, Naor, Moni, editor, Nierstrasz, Oscar, editor, Pandu Rangan, C., editor, Steffen, Bernhard, editor, Sudan, Madhu, editor, Terzopoulos, Demetri, editor, Tygar, Dough, editor, Vardi, Moshe Y., editor, Weikum, Gerhard, editor, and Yakhno, Tatyana, editor

Published
2005
Full Text
View/download PDF

28. Lost Retransmission Detection for TCP Part 1: TCP Reno and NewReno

Author

Kim, Beomjoon, Choi, Yong-Hoon, Park, Jaesung, Hutchison, David, editor, Kanade, Takeo, editor, Kittler, Josef, editor, Kleinberg, Jon M., editor, Mattern, Friedemann, editor, Mitchell, John C., editor, Naor, Moni, editor, Nierstrasz, Oscar, editor, Pandu Rangan, C., editor, Steffen, Bernhard, editor, Sudan, Madhu, editor, Terzopoulos, Demetri, editor, Tygar, Dough, editor, Vardi, Moshe Y., editor, Weikum, Gerhard, editor, Freire, Mário Marques, editor, Chemouil, Prosper, editor, Lorenz, Pascal, editor, and Gravey, Annie, editor

Published
2004
Full Text
View/download PDF

29. On the Efficacy of PPPMux Within Radio Access Network

Author

Park, Jaesung, Kim, Beomjoon, Choi, Yong-Hoon, Hutchison, David, editor, Kanade, Takeo, editor, Kittler, Josef, editor, Kleinberg, Jon M., editor, Mattern, Friedemann, editor, Mitchell, John C., editor, Naor, Moni, editor, Nierstrasz, Oscar, editor, Pandu Rangan, C., editor, Steffen, Bernhard, editor, Sudan, Madhu, editor, Terzopoulos, Demetri, editor, Tygar, Dough, editor, Vardi, Moshe Y., editor, Weikum, Gerhard, editor, Freire, Mário Marques, editor, Chemouil, Prosper, editor, Lorenz, Pascal, editor, and Gravey, Annie, editor

Published
2004
Full Text
View/download PDF

30. End-to-End Quality of Service Monitoring Using ICMP and SNMP

Author

Choi, Yong-Hoon, Kim, Beomjoon, Park, Jaesung, Hutchison, David, editor, Kanade, Takeo, editor, Kittler, Josef, editor, Kleinberg, Jon M., editor, Mattern, Friedemann, editor, Mitchell, John C., editor, Naor, Moni, editor, Nierstrasz, Oscar, editor, Pandu Rangan, C., editor, Steffen, Bernhard, editor, Sudan, Madhu, editor, Terzopoulos, Demetri, editor, Tygar, Dough, editor, Vardi, Moshe Y., editor, Weikum, Gerhard, editor, Freire, Mário Marques, editor, Chemouil, Prosper, editor, Lorenz, Pascal, editor, and Gravey, Annie, editor

Published
2004
Full Text
View/download PDF

31. Modeling TCP Loss Recovery Latency with the Number of Retransmissions

Author

Kim, Beomjoon, Park, Jaesung, Choi, Yong-Hoon, Hutchison, David, editor, Kanade, Takeo, editor, Kittler, Josef, editor, Kleinberg, Jon M., editor, Mattern, Friedemann, editor, Mitchell, John C., editor, Naor, Moni, editor, Nierstrasz, Oscar, editor, Pandu Rangan, C., editor, Steffen, Bernhard, editor, Sudan, Madhu, editor, Terzopoulos, Demetri, editor, Tygar, Dough, editor, Vardi, Moshe Y., editor, Weikum, Gerhard, editor, Aykanat, Cevdet, editor, Dayar, Tuǧrul, editor, and Körpeoğlu, İbrahim, editor

Published
2004
Full Text
View/download PDF

32. A Performance Evaluation of PPP Multiplexing Within UTRAN

Author

Park, Jaesung, Kim, Beomjoon, Choi, Yong-Hoon, Hutchison, David, editor, Kanade, Takeo, editor, Kittler, Josef, editor, Kleinberg, Jon M., editor, Mattern, Friedemann, editor, Mitchell, John C., editor, Naor, Moni, editor, Nierstrasz, Oscar, editor, Pandu Rangan, C., editor, Steffen, Bernhard, editor, Sudan, Madhu, editor, Terzopoulos, Demetri, editor, Tygar, Dough, editor, Vardi, Moshe Y., editor, Weikum, Gerhard, editor, Yang, Laurence T., editor, Guo, Minyi, editor, Gao, Guang R., editor, and Jha, Niraj K., editor

Published
2004
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results