• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.39B no.11
• /
• pp.743-754
• /
• 2014

Recently, Information-Centric Networking(ICN), different from traditional IP-based networking, has been highlighted. Content-Centric Networking(CCN), proposed by Van Jacobson, is a representative scheme of the ICN architectures. It can deliver messages slightly faster than the IP-based networking by focusing on the access and delivery to the content itself. However, CCN is restricted to distribute the information without transmitting the request packet in advance because it is pull-based architecture by content requester. In addition, it has a problem that the Pending Interest Table(PIT) could be overloaded easily when DDoS attack happens. In this paper, we suggest an algorithm using a push-based scheme without request packets and overcoming PIT overload situation by Interest Group Push Table(IGPT). The proposed scheme enables to transmit a large amount of content than an existing scheme during the same amount of time in terms of timely-delivery and security.

• Journal of Communications and Networks
• /
• v.17 no.6
• /
• pp.549-557
• /
• 2015

Mobile cellular networks are becoming increasingly complex to manage while classical deployment/optimization techniques and current solutions (i.e., cell densification, acquiring more spectrum, etc.) are cost-ineffective and thus seen as stopgaps. This calls for development of novel approaches that leverage recent advances in storage/memory, context-awareness, edge/cloud computing, and falls into framework of big data. However, the big data by itself is yet another complex phenomena to handle and comes with its notorious 4V: Velocity, voracity, volume, and variety. In this work, we address these issues in optimization of 5G wireless networks via the notion of proactive caching at the base stations. In particular, we investigate the gains of proactive caching in terms of backhaul offloadings and request satisfactions, while tackling the large-amount of available data for content popularity estimation. In order to estimate the content popularity, we first collect users' mobile traffic data from a Turkish telecom operator from several base stations in hours of time interval. Then, an analysis is carried out locally on a big data platformand the gains of proactive caching at the base stations are investigated via numerical simulations. It turns out that several gains are possible depending on the level of available information and storage size. For instance, with 10% of content ratings and 15.4Gbyte of storage size (87%of total catalog size), proactive caching achieves 100% of request satisfaction and offloads 98% of the backhaul when considering 16 base stations.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.11 no.8
• /
• pp.1434-1441
• /
• 2007

Recently Digital Content has been to product, process and circulate fast. Also Environment and personality of user who consume digital content have been to diversify. These would be provide customized digital content to satisfy user request following specific character, environment and personality of user. In this paper, We design and implement customized content creation and consumption based on DID of MPEG-21 framework which is processing the standardization in MPEG. It filled in standard document md packaging according to the selection of the user.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.39B no.12
• /
• pp.817-821
• /
• 2014

As users generate lots of contents independently of time and places anytime and anywhere together with a rapid development of mobile wireless communication technologies and an explosive dissemination of smart devices, content centric networking (CCN) has emerged as a new networking architecture. However, as CCN is based on one to one message exchanges, it is not appropriate for ad hoc network environment that has frequent network topology changes, which results in high control overhead and low transmission throughput. So, this paper proposes the new content sharing methods using group interest messages in CCN ad hoc environment. It is shown from the simulation that the proposed method can provide low control overhead and high transmission throughput.

• Journal of Broadcast Engineering
• /
• v.25 no.1
• /
• pp.25-35
• /
• 2020

Recently, the development of image processing technology, as well as hardware performance, has been continuing the research on 3D point processing technology that provides users with free viewing angle and stereoscopic effect in various fields. Point cloud technology, which is a type of representation of 3D point, has attracted attention in various fields because it can acquired/expressed point precisely. However, since Hundreds of thousands, millions of point are required to represent one 3D point cloud content, there is a disadvantage that a larger amount of storage space is required than a conventional 2D content. For this reason, the MPEG (Moving Picture Experts Group), an international standardization organization, is continuing to research how to efficiently compress, store, and transmit 3D point cloud content to users. In this paper, a V-PCC bitstream generated by a V-PCC (Video-based Point Cloud Compression) encoder proposed by the MPEG-I (Immersive) group is composed of an MPU (Media Processing Unit) defined by the MMT. In addition, by extending the signaling message defined in the MMT standard, a parameter for a segmented transmission method of the 3D point cloud content by area and quality parameters considering the characteristic of the 3D point cloud content, so that the quality parameters can be selectively determined according to the user's request. Finally, in this paper, we verify the result through design/implementation of the verification platform based on the proposed technology.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2007.06a
• /
• pp.101-104
• /
• 2007

Digital content increased much according to the development of an information technique and internet. Many content services are appearing therefore. These would be provide customized digital content to satisfy user request following specific character of user. A digital content must be provided to the structure to be standardized for this. The expression is possible this in MPEG to DID of MPEG-21 framework which is processing the standardization. In this paper, We designed and implemented module that possible to create meta data and to package Digital Item via MPEG-21 DID Standardization based on selected information of consumer.

• Journal of Korean Academy of Nursing
• /
• v.47 no.3
• /
• pp.392-405
• /
• 2017

Purpose: This study aims to develop a self-reflection program for nurses who have experienced the death of pediatric patients in the intensive care unit and to evaluate its effectiveness. Methods: The self-reflection program was developed by means of the following four steps: establishment of the goal through investigation of an initial request, drawing up the program, preliminary research, and implementation and improvement of the program. The study employed a methodological triangulation to evaluate the effectiveness of the program. Participants were 38 nurses who had experienced the death of pediatric patients (experimental group=15, control group=23); they were recruited using convenience sampling. The self-reflection program was provided over 6 weeks (6 sessions). Data were collected from April to August, 2014 and analyzed using t-tests and content analysis. Results: The quantitative results showed that changes in personal growth (t=-6.33, p<.001) and burnout scores (z=-2.76, p=.005) were better in the experimental group compared to the control group. The qualitative results exhibited two themes, namely "personal growth" and "professional growth", and ten sub-themes. Conclusion: The self-reflection program developed by this study was effective in helping nurses who had experienced the death of pediatric patients to achieve personal growth through self-reflection, and it was confirmed that the program can be applied in a realistic clinical nursing setting. Furthermore, it can be recommended as an intervention program for clinical nurses.

• Journal of Broadcast Engineering
• /
• v.23 no.6
• /
• pp.813-823
• /
• 2018

UHD content is characterized by higher bandwidth requirements to provide seamless playback. The existing HTTP adaptive streaming scheme periodically requests video segment of lower quality than the available bandwidth in the steady state. In the steady state, the On-Off pattern is repeated due to the difference of the available bandwidth and the encoding rate of the content. And the repeated Off interval is causing the problem that can not efficiently use the available bandwidth. In the wireless environment where the delay and loss rate are higher with large bandwidth fluctuations, this problem is exacerbated because the available bandwidth is estimated inaccurately. Therefore, in this paper, we propose a segment scheduling scheme for efficient bandwidth utilization of UHD contents streaming in wireless environment. Proposed scheme is a group segment that simultaneously reqeusts multiple segments in one request message in order to reduce frequency of OFF interval. Through simulation, Our scheme improves bandwidth utilization.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.14 no.11
• /
• pp.4372-4394
• /
• 2020

The distribution of popular videos incurs a large amount of traffic at the base stations (BS) of networks. Device-to-multi-device (D2MD) communication has emerged an efficient radio access technology for offloading BS traffic in recent years. However, traditional studies have focused on synchronous user requests whereas asynchronous user requests are more common. Hence, offloading BS traffic in case of asynchronous user requests while considering their time-varying characteristics and the quality of experience (QoE) of video request users (VRUs) is a pressing problem. This paper uses social stability (SS) and video loading duration (VLD)-tolerant property to group VRUs and seed users (SUs) to offload BS traffic. We define the average amount of data transmission (AADT) to measure the network's capacity for offloading BS traffic. Based on this, we formulate a time-varying bipartite graph matching optimization problem. We decouple the problem into two subproblems which can be solved separately in terms of time and space. Then, we propose the socially aware D2MD user selection (SA-D2MD-S) algorithm based on finite horizon optimal stopping theory, and propose the SA-D2MD user matching (SA-D2MD-M) algorithm to solve the two subproblems. The results of simulations show that our algorithms outperform prevalent algorithms.

• Journal of the Korean Home Economics Association
• /
• v.35 no.4
• /
• pp.125-138
• /
• 1997

The purpose of this study was to explore the types of mother's language and literacy information as they collaborated to write a letter during a 10-minute session. Subjects of the study consisted of 60 mothers and their children 10 boys and 10 girls each at the age of 3,4 and 5 The mothers' teaching language was analyzed on the basis of hoffman(1987)'s study and the types of information thant mothers and children exchanged during writing letters was analyzed by Burns and Casbergue (1992)'s categories. Frequency percentages and χ2 tests were used to analyze the data. The resuls of this study were as follows. 1. The types of the mothers' teaching language from the most to the least were mother-initiated statements mother-initiated questions and mother's responses to child's efforts. There were significant differences according to children's age in mothers' language. In the mother-initiated questions request questions were used most frequently and followed by interrogation questions and invitation questions next. The statements initiated by mothers were directive comments informative comments supportive comments insistence comments and invitation comments in order. Mothers' responses to child's efforts were corrects/controls additional cues confirmation promotion and praise in order. In all three types of the teaching language significant promotion and praise in order. In all three types of the teaching language significant differences were found according to children's age. 2. The types of information about writing were spelling content off task/preparation mechanical conventions and conceptual meaning of writing in order. Significant differences were found according to children's age. In the age group of 4-and 5-year-olds the mothers exchanged more information about spelling than the mothers of 3-years-olds who frequently used information about content and off task or preparation of writing the letter.