Changki Lee

Prof. Changki Lee

orcid

Research Focus & Metrics

Academic Career Length

13Years (2014-Present)

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

Representative Publications

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20 May 2020 in Sensors
Verified
Journal Article
Open access
PDF file
SCSunoh Choi
Sunoh Choi
JBJangseong Bae
Jangseong Bae
CLChangki Lee
Changki Lee
YKYoungsoo Kim
Youngsoo Kim
JKJonghyun Kim
Jonghyun Kim
Every day, hundreds of thousands of malicious files are created to exploit zero-day vulnerabilities. Existing pattern-based antivirus solutions face difficulties in coping with such a large number of new malicious files. To solve this problem, artificial intelligence (AI)-based malicious file detection methods have been proposed. However, even if we can detect malicious files with high accuracy using deep learning, it is difficult to identify why files are malicious. In this study, we propose a malicious file feature extraction method based on attention mechanism. First, by adapting the attention mechanism, we can identify application program interface (API) system calls that are more important than others for determining whether a file is malicious. Second, we confirm that this approach yields an accuracy that is approximately 12% and 5% higher than a conventional AI-based detection model using convolutional neural networks and skip-connected long short-term memory-based detection model, respectively.

7 April 2019 in ETRI Journal
Verified
Journal Article
Open access
PDF file
CPCheoneum Park
Cheoneum Park
CLChangki Lee
Changki Lee
LHLynn Hong
Lynn Hong
YHYigyu Hwang
Yigyu Hwang
TYTaejoon Yoo
Taejoon Yoo
HKHyun‐Ki Kim
Hyun‐Ki Kim
Machine reading comprehension is the task of understanding a given context and finding the correct response in that context. A simple recurrent unit (SRU) is a model that solves the vanishing gradient problem in a recurrent neural network (RNN) using a neural gate, such as a gated recurrent unit (GRU) and long short‐term memory (LSTM); moreover, it removes the previous hidden state from the input gate to improve the speed compared to GRU and LSTM. A self‐matching network, used in R‐Net, can have a similar effect to coreference resolution because the self‐matching network can obtain context information of a similar meaning by calculating the attention weight for its own RNN sequence. In this paper, we construct a dataset for Korean machine reading comprehension and propose an S2‐Net model that adds a self‐matching layer to an encoder RNN using multilayer SRU. The experimental results show that the proposed S2‐Net model has performance of single 68.82% EM and 81.25% F1, and ensemble 70.81% EM, 82.48% F1 in the Korean machine reading comprehension test dataset, and has single 71.30% EM and 80.37% F1 and ensemble 73.29% EM and 81.54% F1 performance in the SQuAD dev dataset.

1 January 2017 in IEICE Transactions on Information and Systems
Verified
Journal Article
Open access
PDF file
CLChangki Lee
Changki Lee
Recurrent neural networks (RNNs) are a powerful model for sequential data. RNNs that use long short-term memory (LSTM) cells have proven effective in handwriting recognition, language modeling, speech recognition, and language comprehension tasks. In this study, we propose LSTM conditional random fields (LSTM-CRF); it is an LSTMbased RNN model that uses output-label dependencies with transition features and a CRF-like sequence-level objective function. We also propose variations to the LSTM-CRF model using a gate recurrent unit (GRU) and structurally constrained recurrent network (SCRN). Empirical results reveal that our proposed models attain state-of-the-art performance for named entity recognition.

1 December 2016 in ETRI Journal
Verified
Journal Article
Closed access
PDF file
CPCheoneum Park
Cheoneum Park
KCKyoung-Ho Choi
Kyoung-Ho Choi
CLChangki Lee
Changki Lee
SLSoo-Jong Lim
Soo-Jong Lim

11 April 2018 in ETRI Journal
Verified
Journal Article
Closed access
PDF file
SJSangkeun Jung
Sangkeun Jung
CLChangki Lee
Changki Lee

11 August 2017 in ETRI Journal
Verified
Journal Article
Closed access
PDF file
YYYeochan Yoon
Yeochan Yoon
JLJunwoo Lee
Junwoo Lee
SPSo-Young Park
So-Young Park
CLChangki Lee
Changki Lee