A Hybrid Deep Learning Model to Forecast Particulate Matter Concentration Levels in Seoul, South Korea

Title : A Hybrid Deep Learning Model to Forecast Particulate Matter Concentration Levels in Seoul, South Korea
Journal : Atmosphere
Authors : Guang Yang, HwaMin Lee, Giyeol Lee
These authors contributed equally to this work : Guang Yang, HwaMin Lee
Corresponding author : Giyeol Lee
DOI : https://doi.org/10.3390/atmos11040348

Abstract
Both long- and short-term exposure to high concentrations of airborne particulate matter (PM) severely affect human health. Many countries now regulate PM concentrations. Early-warning systems based on PM concentration levels are urgently required to allow countermeasures to reduce harm and loss. Previous studies sought to establish accurate, efficient predictive models. Many machine-learning methods are used for air pollution forecasting. The long short-term memory and gated recurrent unit methods, typical deep-learning methods, reliably predict PM levels with some limitations. In this paper, the authors proposed novel hybrid models to combine the strength of two types of deep learning methods. Moreover, the authors compare hybrid deep-learning methods (convolutional neural network (CNN)—long short-term memory (LSTM) and CNN—gated recurrent unit (GRU)) with several stand-alone methods (LSTM, GRU) in terms of predicting PM concentrations in 39 stations in Seoul. Hourly air pollution data and meteorological data from January 2015 to December 2018 was used for these training models. The results of the experiment confirmed that the proposed prediction model could predict the PM concentrations for the next 7 days. Hybrid models outperformed single models in five areas selected randomly with the lowest root mean square error (RMSE) and mean absolute error (MAE) values for both PM10 and PM2.5. The error rate for PM10 prediction in Gangnam with RMSE is 1.688, and MAE is 1.161. For hybrid models, the CNN–GRU better-predicted PM10 for all stations selected, while the CNN–LSTM model performed better on predicting PM2.5.

Acknowledgments
This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT and Future Planning (NRF-2017R1A2B4010570) and Soonchunhyang University Research Fund.

CNN and LSTM models for predicting particulate matter in the Republic of Korea

Title : CNN and LSTM models for predicting particulate matter in the Republic of Korea
Published in : The 8th International Conference on Information, System and Convergence Applications International Symposium on Innovation in Information Technology and Application 2020 (ICISCA 2020)
Author : Minsu Chae, Sangwook Han, HwaMin Lee
Corresponding author : HwaMin Lee
Location : Ton Duc Thang University, Ho Chi Minh, Vietnam and Online

Abstract
Recently, fine dust has become a problem all over the world. Many countries set regulations for PM10 and PM2.5. Because fine dust adversely affects human health, it is important to alert PM10 and PM2.5 in each city. Predictions for PM10 and PM2.5 are required to alert. We propose a hybrid model of the CNN(Convolutional Neural Network) model and the LSTM(Long Short-Term Memory) model to predict the PM10 and PM2.5 in the Republic of Korea. In addition, we evaluate the performance of the CNN model, the LSTM model, and the proposed hybrid model. As a result of the performance evaluation, the proposed hybrid model has high accuracy.

Acknowledgments
This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT & Future Planning (NRF-2017R1A2B4010570).

A performance comparison of linux containers and virtual machines using Docker and KVM

Title : A performance comparison of linux containers and virtual machines using Docker and KVM
Journal : Cluster Computing
Authors : MinSu Chae, HwaMin Lee, Kiyeol Lee
Corresponding author : HwaMin Lee
DOI : https://doi.org/10.1007/s10586-017-1511-2

Abstract
Virtualization is a foundational element of cloud computing. Since cloud computing is slower than a native system, this study analyzes ways to improve performance. We compared the performance of Docker and Kernel-based virtual machine (KVM). KVM uses full virtualization, including ×86 hardware virtualization extensions. Docker is a solution provided by isolation in userspace instead of creating a virtual machine. The performance of KVM and Docker was compared in three ways. These comparisons show that Docker is faster than KVM.

Acknowledgments
This work was supported by the National Research Foundation of Korea (NRF) Grant funded by the Korea government (Ministry of Science and ICT) (No. NRF-2017R1A2B4010570) and the Soonchunhyang University Research Fund.

CNN and RNN models for predicting particulate matter in South Korea

Title : CNN and RNN models for predicting particulate matter in South Korea
Published in : The 11th International Conference on Internet (ICONI 2019)
Author : Guang Yang, Thanongsak Xayasouk, HwaMin Lee
Corresponding author : HwaMin Lee
Location : Lotte Hotels & Resorts Hanoi, Hanoi, Vietnam

Abstract
Particulate matter proved to have severe effects on human health. To implement a real-time predicting system for is indispensable for every country face air pollution problem. Based on the previous study, predicting models for local areas are implemented. In this paper, a convolutional network, a recurrent neural network and a hybrid model combines the convolutional layers with the recurrent layers apply to predict future one weeks PM10 and PM2.5 concentration in seven urban cities in South Korea. The main contribution in this paper is: proposed three predicting models, make a comparison of three different models for predicting the concentration of particulate matter, all models are proved capable to obtain reliable predicting results. Experiments show GRU archive best performance for most cities both for PM10 and PM2.5, CNN models speed up the training process with least time consumption. The hybrid model performance stable with less time for training.

Acknowledgments
This research supported by the MSIT(Ministry of Science and ICT), Korea, under the ITRC(Information Technology Research Center) support program(IITP-2019-2015-0-00403) supervised by the IITP(Institute for Information & communications Technology Planning & Evaluation) and Basic Science Research Program through the National Research Foundation of Korea (NRF-2017R1A2B4010570).

Serverless Framework for Efficient Resource Management in Docker Environment

Title : Serverless Framework for Efficient Resource Management in Docker Environment
Journal : Lecture Notes in Electrical Engineering book
Authors : Sangwook Han, Minsu Chae, HwaMin Lee
Corresponding author : HwaMin Lee
DOI : https://doi.org/10.1007/978-981-13-9341-9_32

Abstract
APIs provided by the Docker is executed through the container engine. Thus, it is a reality that the speed of creation and deletion of containers or requests for information is very slow. The load is even worse when many containers sending API requests at once. In this paper, we propose a method to apply module related to resource management in a container to reduce the load on API request generated in serverless environment. And we propose a new framework that manages resources of several containers or multiple Docker serves.

Acknowledgments
This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT & Future Planning (NRF-2017R1A2B4010570) and the Ministry of Science and ICT, Korea, under the ITRC (Information Technology Research Center) support program (IITP-2017-2015-0-00403) supervised by the IITP (Institute for Information & communications Technology Promotion).

크롤링을 이용한 자동매칭 게임톡 웹 서비스

제목 : 크롤링을 이용한 자동매칭 게임톡 웹 서비스
저자 : 반영태, 한상욱, 이도경, 윤건일, 이화민
게재지 : 2019년 한국정보처리학회 추계학술발표대회 논문집
교신저자 : 이화민
장소 : 제주도, 제주대학교
DOI : https://doi.org/10.3745/PKIPS.y2019m10a.1169

초록
최근 많은 이용자들이 음성채팅을 이용하여 게임을 즐긴다. 하지만 많은 사람들이 게임 내에서 지원하는 음성 채팅을 사용하지 않고 별도의 음성 프로그램을 사용하고 있다. 현재 게임 내 음성채팅과 외부 음성채팅 모두 편의 기능이 많이 부족하며, 가장 큰 문제점으로는 사용자 본인이 직접 음성 채팅에 참여하는 유저를 구해야 한다는 것이다. 본 논문에서는 이러한 불편한 상황을 없애기 위하여 자동으로 음성 채팅이 가능한 사람을 모집하여 좀 더 편안한 게임 환경을 제공할 수 있는 음성 채팅 웹 서비스를 개발 하였다. 웹 크롤링 기술을 이용하여 외부 커뮤니티등의 구인 글을 크롤링 하여 설정한 조건과 구인 조건이 일치하면 사이트 사용자 뿐 만 아니라 미사용자 간의 매칭도 빠르게 지원 하도록 개발하였다.

Acknowledgments
이 성과는 2017년도 정부(과학기술정보통신부)의 재원으로 한국연구재단의 지원을 받아 수행된 연구임(NRF-2017R1A2B4010570)
본 연구는 과학기술정보통신부 및 정보통신기술진흥센터의 대학ICT연구센터육성 지원사업의 연구결과로 수행되었음(IITP-2019-2015-0-00403)

Docker-based Cloud System for Computer Programming Labs

Title : Docker-based Cloud System for Computer Programming Labs
Published in : The 14th International Conference on Computer Science & Education (ICCSE 2019)
Author : Minsu Chae, Sangwook Han, HwaMin Lee
Corresponding author : HwaMin Lee
Location : The Oshawa Campus of Durham College and University of Ontario Institute of Technology(UOIT) Durham College, Toronto, Canada
URL : https://ieeexplore.ieee.org/document/8845470

Abstract
Recently, the importance of software education has been emphasized all over the world. In Korea, software education has been introduced for elementary schools that have applied for software education since 2015, and software education has been adopted as a regular subject in all elementary schools since 2017. As the importance of the software industry grows, interest in coding education is increasing. In Korea, students must complete 16 hours of instruction in elementary school and 34 hours in middle school from 2019. In Korea, however, there are not enough professional teachers who majored in software, and many schools have poor laboratory environments. For successful software coding education, a basic hands-on environment should be supported. It is also difficult for the teacher to analyze and score all students’ program sources during class. In this paper, we propose a computer labs management system that can be executed within seconds by using images already generated by Docker for software education at school. And we implemented a programming practice management system using Docker. Our system provides the ability for teachers to automatically identify and score students’ source code as they conduct coding training.

Acknowledgments
This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT & Future Planning (NRF-2017R1A2B4010570) and the ITRC (Information Technology Research Center) support program (IITP-2019-2015-0-00403) supervised by the IITP(Institute for Information & communications Technology Promotion).

Arrhythmia Classification System Using Deep Neural Network

Title : Arrhythmia Classification System Using Deep Neural Network
Published in : The 11th International Conference on Ubiquitous and Future Networks(ICUFN 2019)
Author : EunKwang Jeon, Sangwook Han, MinSu Chae, HwaMin Lee
Corresponding author : HwaMin Lee
Location : SHERATON ZAGREB Hotel, Zagreb, Croatia

Abstract
Previous studies on arrhythmia were used to diagnose the abnormally fast, slow, or irregular heart rhythm through ECG (Electrocardiogram), which is one of the biological signals. ECG has the form of P-QRS-T wave, and many studies have been done to extract the features of QRS-complex and R-R interval. However, in the conventional method, the P-QRS-T wave must be accurately detected, and the feature value is extracted through the P-QRS-T wave. If an error occurs in the peak detection or feature extraction process, the accuracy becomes very low. Therefore, in this paper, we implement a system that can perform PVC (Premature Ventricular Contraction) and PAC (Premature Atrial Contraction) classification by using P-QRS-T peak value without feature extraction process using deep neural network. The parameters were updated for PVC and PAC classification in the learning process using P-QRS-T peak without feature value. As a result of the performance evaluation, we could confirm higher accuracy than the previous studies and omit the process of feature extraction, and the time required for the preprocessing process to construct the input data set is relatively reduced.

Acknowledgments
This research supported by the MSIT (Ministry of Science and ICT), Korea, under the ITRC (Information Technology Research Center) support program (IITP-2019-2014-1-00720) supervised by the IITP(Institute for Information & communications Technology Planning & Evaluation) and Basic Science Research Program through the National Research Foundation of Korea (NRF-2017R1A2B4010570).

A hybrid CNN-RNN model for particulate matter forecasting in Seoul

Title : A hybrid CNN-RNN model for particulate matter forecasting in Seoul
Published in : The 14th Asia Pacific International Conference on Information Science and Technology (APIC-IST 2019)
Author : Guang Yang, Thanongsak Xayasouk, HwaMin Lee
Corresponding author : HwaMin Lee
Location : Grand Gongda JianGuo Hotel, Beijing, China

Abstract
Epidemiological research shows that short-term exposure to air pollution especially particulate matter can damage human health. A reliable predicting model with high accuracy is required. Contribute to building real-time forecasting and alarm system. Previous papers focus on improving accuracy by optimizing a single statistical predicting method. In this paper, a hybrid deep learning model is proposed to predict the future day’s particulate matter concentration in Seoul, South Korea. The proposed model combined RNN with a pre-trained ConvNet to forecast future PM2.5 and PM10 concentrations. CNN used to extract the hidden features and used RNN consisted of the gated recurrent unit to make a prediction. With combine the meteorological data, the proposed model can achieve satisfying accuracy and hold less time to consume compared with the bare RNN network.

Acknowledgments
This research supported by the MSIT(Ministry of Science and ICT), Korea, under the ITRC(Information Technology Research Center) support program (IITP-2019-2015-0-00403) supervised by the IITP(Institute for Information & communications Technology Planning & Evaluation) and Basic Science Research Program through the National Research Foundation of Korea (NRF-2017R1A2B4010570).

Energy efficient VM scheduling for big data processing in cloud computing environments

Title : Energy efficient VM scheduling for big data processing in cloud computing environments
Journal : Journal of Ambient Intelligence and Humanized Computing
Authors : SangWook Han, SeDong Min, HwaMin Lee
Corresponding author : HwaMin Lee
DOI : https://doi.org/10.1007/s12652-019-01361-8

Abstract
Recently, the cloud computing platform has come to be widely used to analyze large amounts of data collected in real-time from SNS or IoT sensors. In order to analyze big data, a large number of VMs are created in the cloud server, and that many PMs are needed to handle it. When VMs are allocated to PMs in cloud computing, each VM is allocated by a VM scheduling algorithm. However, existing scheduling algorithms waste substantial PM resources due to the low density of VM. This waste of resources dramatically reduces the energy efficiency of the entire cloud server. Therefore, minimizing idle PMs by increasing the density of VMs allocated to PMs is critical for VM scheduling. In this paper, a VM relocation method is suggested to improve the energy efficiency by increasing the density of VMs using the Knapsack algorithm. In addition, it is possible through the proposed method to achieve efficient VM relocation in a short period by improving the Knapsack algorithm. Therefore, we proposed the effective resource management method of cloud cluster for big data analysis.

Acknowledgments
This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT and Future Planning (NRF-2017R1A2B4010570) and by the Soonchunhyang University Research Fund.