• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.66 no.8
• /
• pp.1257-1264
• /
• 2017

In video content watching service, when a user requests video content, the content server has to transmit the entire video to the client for watching. This transmission delay increases as the size of video content increases. In order to solve the transmission delay problem, a prefetching technique can be used in which a video content to be watched by a user is predicted and transmitted to a client before the user requests it. In this paper, we propose a prefetching system considering multiple indices for video content. In the proposed method, video content to be prefetched is selected by comprehensively analyzing the order relation index indicating the order of viewing the videos of the users, the similarity index between the video contents, and the popularity index reflecting the viewing frequency of the video content. Experimental results show that the maximum accuracy is achieved when prefetching uses only the order relation index for movie contents.

• International Journal of Internet, Broadcasting and Communication
• /
• v.8 no.1
• /
• pp.33-41
• /
• 2016

Big data management is becoming an increasingly important issue in both industry and academia of information science community today. One of the important categories of big data generated from software systems is log data. Log data is generally used for better services in various service providers and can also be used to improve system reliability. In this paper, we propose a novel big data management architecture specialized for log data. The proposed architecture provides a scalable log management system that consists of client and server side modules for efficient handling of log data. To support large and simultaneous log data from multiple clients, we adopt the Hadoop infrastructure in the server-side file system for storing and managing log data efficiently. We implement the proposed architecture to support various client environments and validate the efficiency through measurement studies. The results show that the proposed architecture performs better than the existing logging architecture by 42.8% on average. All components of the proposed architecture are implemented based on open source software and the developed prototypes are now publicly available.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.12 no.8
• /
• pp.3856-3872
• /
• 2018

HTTP-based adaptive streaming (HAS) has recently been widely deployed on the Internet. In the HAS system, a video content is encoded at multiple bitrates and the encoded video content is segmented into small parts of fixed durations. The HAS client requests a video segment and stores it in the playout buffer. The rate adaptation algorithm employed in HAS clients dynamically determines the video bitrate depending on the time-varying bandwidth. Many studies have shown that an efficient rate adaptation algorithm is critical to ensuring quality-of-experience in HAS systems. However, existing algorithms have problems estimating the network bandwidth because bandwidth estimation is performed on the client-side application stack. Without the help of transport layer protocols, it is difficult to achieve accurate bandwidth estimation due to the inherent segment-based transmission of the HAS. In this paper, we propose an alternative approach that utilizes the playout buffer occupancy rather than using bandwidth estimates obtained from the application layer. We start with a queueing analysis of the playout buffer. Then, we present a buffer-aware rate adaptation algorithm that is solely based on the mean buffer occupancy. Our simulation results show that compared to conventional algorithms, the proposed algorithm achieves very smooth video quality while delivering a similar average video bitrate.

• The Journal of the Korea Contents Association
• /
• v.10 no.12
• /
• pp.342-351
• /
• 2010

This study aims to investigate the major causes of conflict between clients and vendors in the outsourced IS development. A research model is established based on the prior research of IS outsourcing, system development and conflict. An empirical study was executed using 214 survey questionnaire of project teams composed of client and vendor with PASW 18.0. Research results using multiple regressions show that contract specificity, requirements certainty, objective alignment and client knowledge have negative effects on conflict. This research results will provide various implications for outsourcing project success.

• Journal of Digital Contents Society
• /
• v.8 no.4
• /
• pp.579-586
• /
• 2007

The process of developing a online 3D game engine involves designing details of the engine, alpha test, adjustment, supplementation, beta test and introduction, and an online 3D game engine is made of a server engine and client engine. The server engine, which is made of server construction part, distribution center and DB construction part for building asymmetric multiple servers, is developed by Linux, and the client engine, which is made of a graphic part, sound part, AI part and object management part, is developed by using DirectX in Windows, and it proposes an engine configuration and method based on 3D engine technology by analyzing the network technology, which is a common engine technology.

• Journal of Home Health Care Nursing
• /
• v.23 no.2
• /
• pp.243-252
• /
• 2016

Purpose: This study aims to classify multiple forms of home care services from a service user's perspective. By comparing the German system to the Korean one, this study seeks to find better ways of enhancing client-centered care. Methods: The data of 121 home care users were collected from six home care centers that had under the management of nursing managers for more than five years. The researcher used a German instrument to estimate the level of care. Results: High correlation was found between German and Korean assessment criteria (r=0.81, p<.001). However, compared to their German counterparts, Korean home care providers allocated more time towards provision of domestic help per daily visit. German home care providers allocated more time towards services relating to provision of support for physical activities, including personal hygiene. It was confirmed that the level of care in Korea does not correlate with either the categories of home care services and duration. Conclusion: Therefore, care services should be offered according to long-term care needs. This study suggests a need for systematic care aimed at strengthening the client's autonomy which should be properly planned, implemented, and managed.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.6 no.3
• /
• pp.886-905
• /
• 2012

Set-top Box (STB) has evolved from being a device just sitting on top of a TV shelf to a device providing a gateway to the Internet for a home network, receiving services from multiple content providers, and enabling and ensuring Quality of Service (QoS) for the streaming media. IP Multimedia Subsystem (IMS), with its promise to provide a converged access network for multimedia service delivery (such as Triple play & Quadruple play services), has to guarantee QoS support. To enable QoS in IMS-based networks, we have designed a set-top box which provides feedback to the service provider to ensure end-to-end QoS. Our set-top box is designed to provide virtual platforms such that it can support multiple service providers. Each service provider is able to manage its own multimedia streams and ensures the desired network performance for each flow. The set-top box also works as a Home Gateway and provides end-to-end QoS support to the client nodes.

• Journal of Information Technology Services
• /
• v.7 no.1
• /
• pp.167-193
• /
• 2008

Clients' outsourcing strategies noted in the IT outsourcing literature generate varying levels of client dependence on vendors. This study investigates clients' efforts to mitigate such dependence by utilizing multiple vendors. We use the theoretical lenses of resource dependency and opportunism to study this phenomenon. Specifically. we consider degree of outsourcing, duration of contract, and externalization of control as strategic choices that engender vulnerabilities that clients seek to offset by using multiple vendors. This study then considers the basis of the outsourcing relationships, clients' satisfaction with the relationships. and clients' IT workforce size as conditions that induce clients' concerns about vendor opportunism. This study argues that these conditions can exacerbate clients' experience of vulnerability. further encouraging clients' use of multiple vendors. The research model developed is tested in a survey of firms in South Korea. Results suggest a strong impact of outsourcing strategic choices on the number of vendors used by clients. The anticipated moderating effects of opportunism were only weakly supported by the data though. Theoretical and practical implications of the results are considered and suggestions for future research are offered.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2023.05a
• /
• pp.339-341
• /
• 2023

This paper presents a multithread and efficient cryptographic hardware access (MECHA) for efficient and fast cryptographic operations that eliminates the need for context switching. Utilizing a UNIX domain socket, MECHA manages multiple requests from multiple applications simultaneously, resulting in faster processing and improved efficiency. We comprise several key components, including the Server thread, Client thread, Transceiver thread, and a pair of Sender and Receiver queues. MECHA design is portable and can be used with any communication protocol, with experimental results demonstrating a 83% increase in the speed of concurrent cryptographic requests compared to conventional interface design. MECHA architecture has significant potential in the field of secure communication applications ranging from cloud computing to the IoT, offering a faster and more efficient solution for managing multiple cryptographic operation requests concurrently.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2010.05a
• /
• pp.463-466
• /
• 2010

In this paper, CCTV based fire surveillance system should aim to development. Advantages and Disadvantages analyzed of Existing sensor-based fire surveillance system and video-based fire surveillance system. To national support U-City, U-Home, U-Campus, etc, spread the ubiquitous environment appropriate to fire surveillance system model and a fire judgement technology. For this study, Microsoft LifeCam VX-1000 using through the capturing images and analyzed for apple and tomato, Finally we used H.264. The client uses the Linux OS with ARM9 S3C2440 board was manufactured, the client's role is passed to the server to processed capturing image. Client and the server is basically a 1:1 video communications. So to multiple receive to video multicast support will be a specification. Is fire surveillance system designed for multiple video communication. Video data from the RGB format to YUV format and transfer and fire detection for Y value. Y value is know movement data. The red color of the fire is determined to detect and calculate the value of Y at the fire continues to detect the movement of flame.