• Annual Conference of KIPS
• /
• 2013.05a
• /
• pp.175-178
• /
• 2013

Mobile Virtual Desktop Infrastructures (mVDI) are gaining popularity in cloud computing by allowing mobile devices to execute their mobile applications in a cloud server instead of relying on physical mobile devices. Consolidating many users into mVDI environment can significantly lower IT management expenses and enables new features such as "available-anywhere" desktops. However, there are many barriers to broad adoption including the slow performance of virtualized I/O, CPU scheduling interference problems. In this paper, we will discuss about mVDI with the current issues, the corresponding solutions and challenges.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.18 no.6B
• /
• pp.249-257
• /
• 2008

Nowadays, client-to-client applications such as online chat (e.g. MSN) and SMS (Short Message Services) are becoming increasingly prevalent. These client-to-client applications are revolutionizing the way we communicate. Three-party PAKE (password authenticated key exchange) protocols provide a means for the two communicating parties holding passwords to establishment a secure channel between them with the help of a common server. In this paper, we propose an efficient three-party PAKE protocol for the client-to-client applications, which has much better performance than the existing generic constructions. We also show that the proposed protocol is secure in a formal security model.

• Smart Media Journal
• /
• v.12 no.3
• /
• pp.68-76
• /
• 2023

Emerging mobile edge computing (MEC) can be used in battery-constrained Internet of things (IoT). The execution latency of IoT applications can be improved by offloading computation-intensive tasks to an MEC server. Recently, the popularity of unmanned aerial vehicles (UAVs) has increased rapidly, and UAV-based MEC systems are receiving considerable attention. In this paper, we propose a dynamic computation offloading paradigm for UAV-based MEC systems, in which a UAV flies over an urban environment and provides edge services to IoT devices on the ground. Since most IoT devices are energy-constrained, we formulate our problem as a Markov decision process considering the energy level of the battery of each IoT device. We also use model-free Q-learning for time-critical tasks to maximize the system utility. According to our performance study, the proposed scheme can achieve desirable convergence properties and make intelligent offloading decisions.

• Journal of Korea Society of Industrial Information Systems
• /
• v.15 no.5
• /
• pp.63-69
• /
• 2010

Forecasting game usages hours can supply good information resolving intensive server access and ensuring stable game service. In this paper, we applied various time series analysis methods to forecast game usage hours in 2009 on famous "Ion" and "Sudden Attack" games. According to the experiment, the seasonal variation method showed better performance forecasting actual usage hours.

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2020.07a
• /
• pp.714-716
• /
• 2020

We propose a unique client-driven music genre classification solution, that can identify the music genre using a deep convolutional neural network operating on the time-domain signal. The proposed method uses the client device (Jetson TX2) computational resources to identify the music genre. We use the industry famous GTZAN genre collection dataset to get reliable benchmarking performance. HTTP live streaming (HLS) client and server sides are designed locally to validate the effectiveness of the proposed method. HTTP persistent broadcast connection is adapted to reduce corresponding responses and network bandwidth. The proposed model can identify the genre of music files with 97% accuracy. Due to simplicity and it can support a wide range of client hardware.

• Journal of Information Processing Systems
• /
• v.18 no.6
• /
• pp.741-754
• /
• 2022

Openstack is widely used as a representative open-source infrastructure of the service (IaaS) platform. The Openstack Identity Service is a centralized approach component based on the token including the Memcached for cache, which is the in-memory key-value store. Token validation requests are concentrated on the centralized server as the number of differently encrypted tokens increases. This paper proposes the practical Byzantine fault tolerance (PBFT) blockchain-based Openstack Identity Service, which can improve the performance efficiency and reduce security vulnerabilities through a PBFT blockchain framework-based decentralized approach. The experiment conducted by using the Apache JMeter demonstrated that latency was improved by more than 33.99% and 72.57% in the PBFT blockchain-based Openstack Identity Service, compared to the Openstack Identity Service, for 500 and 1,000 differently encrypted tokens, respectively.

• ETRI Journal
• /
• v.45 no.4
• /
• pp.666-677
• /
• 2023

In the last few years, convolutional neural networks (CNNs) have demonstrated good performance while solving various computer vision problems. However, since CNNs exhibit high computational complexity, signal processing is performed on the server side. To reduce the computational complexity of CNNs for edge computing, a lightweight algorithm, such as a MobileNet, is proposed. Although MobileNet is lighter than other CNN models, it commonly achieves lower classification accuracy. Hence, to find a balance between complexity and accuracy, additional hyperparameters for adjusting the size of the model have recently been proposed. However, significantly increasing the number of parameters makes models dense and unsuitable for devices with limited computational resources. In this study, we propose a novel MobileNet architecture, in which the number of parameters is adaptively increased according to the importance of feature maps. We show that our proposed network achieves better classification accuracy with fewer parameters than the conventional MobileNet.

• Annual Conference of KIPS
• /
• 2008.05a
• /
• pp.589-592
• /
• 2008

최근 대부분의 기업은 인터넷 웹 서비스를 하고 있고, 대부분의 인터넷 사용자들이 여러 종류의 웹 서비스를 제공받고 있다. 하지만 사용자들이 필요로 하는 서비스는 한정되어 있지만 대부분의 기업에서는 여러 가지 서비스를 제공하여 다양한 많은 사용자들의 요구를 수용하고자 한다. 그로 인해 초기 메인 웹 페지이에 많은 링크가 연결된 페이지를 제공하게 된다. 이는 초기 웹페이지의 로딩에 있어 큰 용량의 소스가 원인이 되어 다수의 사용자가 짧은 시간에 접속할 경우 서비스 오류의 원인이 되기도 한다. 또한 대부분의 사용자들이 필요로 하는 몇 개의 링크 기능만을 제공하고 니즈가 적은 링크 기능은 비활성화 함으로써 사용자 요구에 좀 더 빠르게 대응할 수 있도록 링크 맵 프로그램을 이용한 웹 시스템을 제안하고 웹 서버의 성능 향상을 연구한다.

• Annual Conference of KIPS
• /
• 2008.05a
• /
• pp.215-218
• /
• 2008

인터넷 사용자의 폭발적인 증가 및 기업의 모든 활동에 있어 이를 지원하는 컴퓨터 정보 시스템의 중요성은 무엇보다도 중요시 되고 있으며 이를 운영하는 관리자의 역할이 더욱더 커지고 있다. 기업의 모든 시스템은 데이터센터라는 곳에서 취합 운영되는 추세이며 데이터센터의 관리자는 시스템의 Health Check를 통하여 시스템을 사용하는 사용자에게 최적의 서비스를 제공해야 한다. 하지만 시스템의 복잡성으로 인하여 시스템을 구성하는 서버의 이상유무를 일일이 파악하는 것은 쉽지가 않다. 이 연구에서는 서버가 운영되면서 발생되는 로그를 수집하여 이를 데이터마이닝의 의사결정트리를 구성하고 서버의 성능로그를 분석하여 서버의 이상 및 병목 유무를 파악하고 아울러 병목을 미리 예측하는 데에 방안을 제시한다.

• Journal of Information Processing Systems
• /
• v.19 no.5
• /
• pp.702-712
• /
• 2023

Load balancing plays a crucial role in ensuring the stable operation of information management systems during periods of high user access requests; therefore, load balancing approaches should be reasonably selected. Moreover, appropriate load balancing techniques could also result in an appropriate allocation of system resources, improved system service, and economic benefits. Nginx is one of the most widely used loadbalancing software packages, and its deployment is representative of load-balancing application research. This study introduces Nginx into an educational administration system, builds a server cluster, and compares and sets the optimal cluster working strategy based on the characteristics of the system, Furthermore, it increases the stability of the system when user access is highly concurrent and uses the Nginx reverse proxy service function to improve the cluster's ability to resist illegal attacks. Finally, through concurrent access verification, the system cluster construction becomes stable and reliable, which significantly improves the performance of the information system service. This research could inform the selection and application of load-balancing software in information system services.