• ETRI Journal
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• v.36 no.5
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• pp.819-828
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• 2014

To solve the increasing popularity of video streaming services over the Internet, recent research activities have addressed the locality of content delivery from a network edge by introducing a storage module into a router. To employ in-network caching and persistent request routing, this paper introduces a hybrid content delivery network (CDN) system combining novel content routers in an underlay together with a traditional CDN server in an overlay. This system first selects the most suitable delivery scheme (that is, multicast or broadcast) for the content in question and then allocates an appropriate number of channels based on a consideration of the content's popularity. The proposed scheme aims to minimize traffic volume and achieve optimal delivery cost, since the most popular content is delivered through broadcast channels and the least popular through multicast channels. The performance of the adaptive scheme is clearly evaluated and compared against both the multicast and broadcast schemes in terms of the optimal in-network caching size and number of unicast channels in a content router to observe the significant impact of our proposed scheme.

• ETRI Journal
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• v.36 no.2
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• pp.197-205
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• 2014

This paper proposes a novel framework for virtual content delivery networks (CDNs) based on cloud computing. The proposed framework aims to provide multimedia content delivery services customized for content providers by sharing virtual machines (VMs) in the Infrastructure-as-a-Service cloud, while fulfilling the service level agreement. Furthermore, it supports elastic virtual CDN services, which enables the capabilities of VMs to be scaled to encompass the dynamically changing resource demand of the aggregated virtual CDN services. For this, we provide the system architecture and relevant operations for the virtual CDNs and evaluate the performance based on a simulation.

• Journal of Korea Multimedia Society
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• v.19 no.8
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• pp.1597-1608
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• 2016

Recently, a number of solutions were proposed to address the challenges and issues of vehicular networks. Vehicular Cloud Computing (VCC) is one of the solutions. The vehicular cloud computing is a new hybrid technology that has a remarkable impact on traffic management and road safety by instantly using vehicular resources. In this paper, we study an important vehicular cloud service, content-based delivery, that allows future vehicular cloud applications to store, share and search data totally within the cloud. We design a VCC-based system architecture for efficient sharing of vehicular contents, and propose a Hierarchical Hybrid Content Delivery scheme using Bloom Filter (H2CDBF) for efficient vehicular content delivery in Vehicular Ad-hoc Networks (VANETs). The performance of the proposed H2CDBF is evaluated through an analytical model, and is compared to the proactive content discovery scheme, Bloom-Filter Routing (BFR).

• The Journal of the Korea Contents Association
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• v.21 no.8
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• pp.10-19
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• 2021

In CCVN, the existing content search and delivery protocols based on single-hop or multi-hop cause low content search ratio and high network traffic overhead. This paper proposes a RSU-based protocol for efficient content search and delivery. In the proposed protocol, an RSU chooses the candidate provider vehicle that provides the cost-minimized content delivery to the content requester vehicle. Simulation results verify that the proposed protocol achieves better performances.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.5
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• pp.764-771
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• 2018

This study focused on shape attributes in a basic study that identified infographics expression diversification and delivery efficiency based on formative attributes. To achieve that goal, formative attributes were categorized as geometric or expressional type, and significant differences between them were found by identifying the attributes of each type. The study analyzed the correlations between each infographic type's formative attributes and content delivery. The results found that regularity, clarity, visibility, and content delivery were attributes of the geometric type, whereas expressionality, visibility, clarity, and content delivery were attributes of the expressional type. Further analysis of the attributes focusing on content delivery found that regularity and visibility significantly influenced content delivery for the geometric type, and expressionality and clarity significantly influenced content delivery for the expressional type. Thus, this study empirically confirmed that formative attributes of infographics distinguished between expression types with statistically significant differences during the visualization process. And that specific factors influencing content delivery were formative attributes.

• Journal of Communications and Networks
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• v.15 no.2
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• pp.198-206
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• 2013

Recent advances in forward error correction (FEC) coding techniques were focused on addressing the challenges of multicast and broadcast delivery. However, FEC approaches can also be used for unicast content delivery in order to solve transmission control protocol issues found in wireless networks. In this paper, we exploit the error resilient properties of Raptor codes by proposing Raptor-based content delivery protocol (RCDP) - a novel solution for reliable and bidirectional unicast communication in lossy links that can improve content delivery in situations where the wireless network is the bottleneck. RCDP has been designed, validated, optimized, and its performance has been analyzed in terms of throughput and resource efficiency. Experimental results show that RCDP is a highly efficient solution for environments characterized by high delays and packet losses making it very suitable for intelligent transport system oriented applications since it achieves significant performance improvements when compared to traditional transport layer protocols.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.5 no.11
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• pp.2143-2159
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• 2011

The hybrid architecture of content delivery networks (CDN) and peer-to-peer overlay networks (P2P) is a promising technology enables effective real-time streaming services. It complements the advantages of quality control and reliability in a CDN, and the scalability of a P2P system. With real-time streaming services, however, high connection setup and media delivery latency are becoming the critical issues in deploying the CDN-P2P system. These issues result from biased peer selection without location awareness or content awareness, and can lead to significant service disruption. To reduce service disruption latency, we propose a group-based CDN-P2P hybrid architecture (iCDN-P2P) with a location/content-aware selection of peers. Specifically, a SuperPeer network makes a location-aware peer selection by employing a content addressable network (CAN) to distribute channel information. It also manages peers with content awareness, forming a group of peers with the same channel as the sub-overlay. Through a performance evaluation, we show that the proposed architecture outperforms the original CDN-P2P hybrid architecture in terms of connection setup delay and media delivery time.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.4C
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• pp.262-268
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• 2005

The unit of the digital content delivery is the web object. For the improvement of the content delivery based on the web, it id required analysis of reference characteristics of the web object. In this study, we analyze reference characteristics of the web object and evaluate the performance. Using these analysis results, we propose the digital content delivery system which is improved delivery efficiency. The goal of the proposed system are the improvement of the processing time through enhancement of the caching efficiency with reflect reference characteristics of the web object. And the experiment result, we verify the performance enhancement.

• The Journal of the Korean dental association
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• v.13 no.6
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• pp.563-567
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• 1975

This present investigation was concerned with the content of collagen and minerals of incisor and molar dentin in rats of differednt ages. The results obtained were summarized as follows. 1. There was no remarked change in the content of collagen-hydroxyproline of incisor and molar dentin according to days after delivery. 2. The Ca content in incisor dentin rose from approximately 15.4% of the dry weight in 7 days after delivery to 21.1% in 22 days while that in molar dentin from 17.6% in 7 days to 19.7% in 22 days. 3. The P content in molar dentin rose from 8.5% in 7 days after delivery to 11.65% in 22 days. while in incisor rose from 8.05% in 7 days to 11.85 in 22 day after delivery.

• Journal of Information Processing Systems
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• v.10 no.1
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• pp.81-91
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• 2014

Widely spreading smart devices have become an important information sharing channel in everyday life. In particular, social networking services (SNS) are the hub for content creation and sharing. Users post their contents on SNS servers and receive contents of interest. Contents are delivered in either pull or push. Regarding delivery, cost and wait time are two important factors to be minimized, but they are in a trade-off relationship. The Push-N-scheme (PNS) and timeout-based push scheme (TPS) have been proposed for content delivery. PNS has an advantage in cost over TPS, whereas TPS has an edge in terms of the wait time over PNS. We propose a hybrid push scheme of PNS and TPS, called push-N-scheme with timeout (PNT), to balance the cost and the wait time. We evaluate PNT through simulations, with the results showing that PNT is effective in balancing PNS and TPS.