• Information and Communications Magazine
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• v.30 no.3
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• pp.67-72
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• 2013

본 고에서는, 미래 인터넷 (Future Internet) 연구에 있어서, 가장 많은 관심과 가능성 예측에 기반한 실제적인 투자를 이끌어 내고 있는 두 개의 주요 핵심 기술 분야인 콘텐츠 중심 네트워킹 (Content-Centric Networking: CCN)과 소프트웨어 정의 네트워킹 기술 (Software-Defined Networking: SDN)의 접목에 대해서, 그 배경과 당위성 그리고 관련 연구 동향을 살펴 본다.

• Clinical and Experimental Reproductive Medicine
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• v.32 no.3
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• pp.269-277
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• 2005

Objectives: Previously, we sought to compile a list of genes expressed during early folliculogenesis by using cDNA microarray to investigate follicular gene expression and changes during primordialprimary follicle transition and development of secondary follicles (Yoon et al., 2005). Among those genes, a group of genes related to the cell size growth was characterized during the ovarian development in the present study. Methods: We determined ovarian expression pattern of six genes related to the cell size growth (cyr61, emp1, fhl1, socs2, wig1 and wisp1) and extended into CCN family (${\underline{c}}onnective$ tissue growth factor/${\underline{c}}ysteine$-rich 61/${\underline{n}}ephroblastoma$-overexpressed), ctgf, nov, wisp2, wisp3, including cyr61 and wisp1 genes. Expression of mRNA and protein according to the ovarian developmental stage was evaluated by in situ hybridization, and/or semiquantitative reverse transcriptase polymerase chain reaction (RT-PCR), and immunohistochemistry, respectively. Results: Among 6 genes related to the cell size growth, cyr61 and wisp1 mRNA was detected only in oocytes in the postnatal day5 mouse ovaries. cyr61 mRNA expression was limited to the nucleolus of oocytes, while wisp1 was expressed in the cytoplasm and nucleolus of oocytes, except nucleus. cyr61 mRNA expression, however, was found in granulosa cells from secondary follicles. The rest 4 genes in the cell size growth group were detected in oocytes, granulosa and theca cells. Cyr61 and Wisp1 proteins were expressed in the oocyte cytoplasm from primordial follicle stage. Especially, Cyr61 protein was detected in pre-granulosa cells, Wisp1 protein was not. By using RT-PCR, we evaluated and decided that Cyr61 protein is produced by their own mRNA in pre-granulosa cells that was not detected by in situ hybridization. cyr61 and wisp1 genes are happen to be the CCN family members. The other members of CCN family were also studied, but their expression was detected in oocytes, granulose and theca cells. Conclusions: We firstly characterized the ovarian expression of genes related to the cell size growth and CCN family according to the early folliculogenesis. Cyr61 protein expression in the pre-granulosa cells is profound in meaning. Further functional analysis for cyr61 in early folliculogenesis is under investigation.

• Korean Journal of Environmental Biology
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• v.39 no.3
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• pp.329-335
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• 2021

Chinese cabbage fields have been damaged by cyst nematodes in highland of Gangwon province in Korea since the year 2011, and clover cyst nematode (CCN) is one of the most problematic cyst nematodes in the crop. To investigate the plant resources for breeding new Chinese cabbage cultivar, which is resistant to CCN, screening for resistance of fifty-seven Brassicaceae plant resources to CCN was conducted. Among the plant resources, fifty-four plant resources (Brassica rapa subsp. pekinensis, B. rapa, Brassica sp., B. juncea, B. carinata, B. rapa subsp. nipposinica, B. rapa subsp. narinosa, B. rapa var. perviridis, B. rapa var. perviridis, B. napus var. napobrassica, and Eruca sativa) were very susceptible to CCN and the number of females on roots was more than 300. Two plant resources (B. carinata and B. tournefortii) with more than 100 females on roots were susceptible to CCN. However, African mustard (B. tournefortii, Korean Genebank accession no. IT218058) was resistant to CCN because of the small number of females (4±1.8) on roots. This study showed that African mustard (IT218058) was valuable as a breeding material for Chinese cabbage, which is resistant to CCN.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.11
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• pp.2151-2159
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• 2015

Unlike an existing IP routing methods, the Content Centric Network(CCN) is new networking paradigm to find the contents by content name. The CCN can effectively process the content requested repeatedly by the user because of the cache which can be storing a content. This paper proposes a popularity based cache replacement scheme. The proposed scheme improves the hit rate better than a existing scheme. Accordingly reducing the load of server and Round Trip Time(RTT).

• The Journal of the Korea Contents Association
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• v.16 no.4
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• pp.224-230
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• 2016

Recently, CCN(Content Centric Network) has been extensively interested in the literature to transfer data traffic efficiently according to the rapid growth of multimedia services on the Internet. CCN is a new networking paradigm to deliver contents efficiently based on the named content not the named or addressed host. This paper presents a mathematical approach for analyzing CCN-caching systems with two routers. Considering the stochastic characteristics of communication networks, the caching system is modeled as a two dimensional Markov chain. This paper analyzes the structural feature of the transition rate matrix in the Markov chain and presents a numerical solution for the CCN-caching performance of the two router system. In addition, various numerical examples are presented.

• Journal of Internet Computing and Services
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• v.18 no.2
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• pp.13-20
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• 2017

Recently, researches to adopt Content-centric network (CCN), which is one of the promising technologies for replacing TCP/IP-based networks, to wireless networks has actively performed. However, because of erroneous and unreliable channel characteristics, there are many problems to be resolved to adopt CCN to wireless networks. This paper proposes a method to reduce content download time because nodes possess only parts of content chunks. The proposed method enables a node having parts of content chunks to request the rest of parts of content chunks to a provider before a Consumer requests the content. As a consequence, the content download time is reduced.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.10
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• pp.2430-2447
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• 2013

In recent years, HTTP adaptive streaming (HAS) has attracted considerable attention as the state-of-the-art technology for video transport. HAS dynamically adjusts the quality of video streaming according to the network bandwidth and device capability of users. Content-Centric Networking (CCN) has also emerged as a future Internet architecture, which is a novel communication paradigm that integrates content delivery as a native network primitive. These trends have led to the new research issue of harmonizing HAS with the in-network caching provided by CCN routers. Previous research has shown that the performance of HAS can be improved by using the H.264/SVC(scalable video codec) in the in-network caching environments. However, the previous study did not address the misbehavior that causes video freeze when overestimating the available network bandwidth, which is attributable to the high cache hit rate. Thus, we propose a new SVC-based adaptation algorithm that utilizes a drop timer. Our approach aims to stop the downloading of additional enhancement layers that are not cached in the local CCN routers in a timely manner, thereby preventing excessive consumption of the video buffer. We implemented our algorithm in the SVC-HAS client and deployed a testbed that could run Smooth-Streaming, which is one of the most popular HAS solutions, over CCNx, which is the reference implementation of CCN. Our experimental results showed that the proposed scheme (SLA) could avoid video freeze in an effective manner, but without reducing the high hit rate on the CCN routers or affecting the high video quality on the SVC-HAS client.

• The Journal of the Convergence on Culture Technology
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• v.4 no.1
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• pp.285-290
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• 2018

Vehicular ad hoc network (VANET) is one of the future communication technologies in which it offers safe-driving information and Internet access for both drivers and passengers by communicating among cars on the road. In case of applying Content Centric Network (CCN) rather than TCP/IP over VANET, called VCCN, it can provide efficient multicast communication of shared information among participating cars as well as offer corresponding one-to-one communications. This paper introduces SUMO for simulating traffic flows, VANET for car-to-car ad hoc communications, and CCN for a future Internet architecture. In addition, it compares and analyses the transmission performance of moving cars over VCCN. According to the simulation results using SUMO and VCCN, the larger the packet size, the better the transmission performance. In addition, VCCN provides higher packet transmission rate than that of TCP/IP when the clients shares the same contents. Furthermore, the overall data reception rate exceeds the physical transmission channel rate.

• KIPS Transactions on Computer and Communication Systems
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• v.7 no.9
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• pp.235-242
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• 2018

Various technologies have been developed to more efficiently share content such as P2P, CDN, and CCN. These technologies take a common approach that content request packets is responded by distributed network nodes or hosts, not by a single content distributor. Such approaches not only resolve network congestion around content distributors, but also make it possible to distribute content regardless of the system and network status of content distributors. However, when receiving content from distributed nodes/hosts, not from authenticated distributors, users cannot practically identify which node/host sent content to them. Due to this characteristic, various hacking caused by the malicious modification of content is possible. Therefore, to make such approaches more secure, a content authentication technique is required. In this paper, we propose a improved operation of MHT used in CCN for authenticating distributed content. Then we evaluate the proposed method by comparing its performance with the existing technology.

• Journal of the Korea Society of Computer and Information
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• v.22 no.4
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• pp.75-82
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• 2017

While the internet has evolved in terms of information sharing and efficiency, it is still prone to security attacks and remains vulnerable even when equipped with a security mechanism. Repeated patching against hacks involves excessive wear of system equipment and high costs. Methods of improving network security include the introduction of security equipment and network partitions, but they have not been fully effective. A fundamental solution is the Operation Content Network (OCN), which enables the strengthening of authentication. In this paper, Instead of following the existing TCP/IP system, OCN establishes an immunity-based security system through content-centric communications. Data transmission occurs over a Content Centric Network (CCN), which is provided with a protocol verified by the CCNx group. Areas protected by OCN rely only on CCN for communication without using any IP. As such, it defends the system against unknown attacks, including zero-day attacks.