• Biomedical Science Letters
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• v.24 no.2
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• pp.64-75
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• 2018

CCN3 (also known as NOV, Nephroblastoma overexpressed) proteins are involved in various pathologies during different developmental stages. We have previously shown that intracellular levels and normal extracellular secretion of CCN3 are important for neuronal differentiation. Furthermore, we demonstrated that a single amino acid in the CCN3 TSP-1 domain is important for extracellular secretion and that palmitoylation of CCN3 is required in this process. However, the effect of abnormal CCN3 accumulation on cells remains to be studied. Here, we found mutations in the TSP-1 domain of CCN3 that led to intracellular accumulation and abnormal aggregation of CCN3. It was observed that this mutation resulted in a phenomenon similar to neurodegeneration when overexpressed in the developing mouse cortex. This mutation also confirmed the activation of apoptotic gene expression in Neuro2a cells. In addition, we confirmed the in vivo transcriptional changes induced by this mutation using microarray analysis. We observed a significant increase in the expression of Anp32a, an apoptosis-related gene. Collectively, these results indicate that a single mutation in CCN3 can lead to abnormal cell death if it shows intracellular accumulation and abnormal aggregation.

• Journal of Animal Reproduction and Biotechnology
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• v.37 no.4
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• pp.255-265
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• 2022

The cellular communication network factor (CCN) family proteins regulate many biological events such as angiogenesis, tumor growth, placentation, implantation, and embryogenesis. The expression and function of CCN1, CCN2, and CCN3 at the maternal-conceptus interface are established in humans and rodents, but little is known about the role of CCN4 to CCN6 in the reproductive organs in any other species. Several studies in transcriptome analysis in pigs have shown that the expression of CCN4 and CCN6 increases in the endometrium during early pregnancy. However, their expression, regulation, and function in the endometrium throughout the estrous cycle and pregnancy have not been fully understood in pigs. Thus, we determined the expression, localization, and regulation of CCN4 and CCN6 during the estrous cycle and at the maternal-conceptus interface in pigs. We found that the levels of CCN4, but not CCN6, changed during the estrous cycle. The levels of CCN4 were greater during mid- to late pregnancy than in the early stage, and the levels of CCN6 were greatest on Day 15 of pregnancy. CCN4 and CCN6 were detected in conceptus tissues during early pregnancy and in chorioallantoic tissues during the later stage of pregnancy. CCN4 mRNA was mainly localized to epithelial cells, CCN6 mRNAs to epithelial and stromal cells in the endometrium. In endometrial explant cultures, CCN4 expression was increased by progesterone, and CCN6 expression by interferon-𝛾. These results suggest that CCN4 and CCN6 may play roles in the establishment and maintenance of pregnancy by regulating the endometrial epithelial cell functions in pigs.

• Information and Communications Magazine
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• v.30 no.3
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• pp.60-66
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• 2013

본고에서는 현 주소 기반 네트워킹 프로토콜의 비효율성을 극복하기 위한 CCN(Content-Centric Networking) 기술이 SNS(Social Networking Service) 플랫폼 구축에 어떻게 활용될 수 있는 지를 살펴 봄으로써, CCN 기술의 유용성과 미래 확산 가능성에 대해 알아본다.

• KIPS Transactions on Computer and Communication Systems
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• v.9 no.3
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• pp.59-66
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• 2020

Content Centric Network(CCN) with architecture that is completely different from traditional host-based networks has emerged to address problems such as the explosion of traffic load in the current network. Research on cache replacement policies is very active to improve the performance of CCN with the characteristics that all routers cache on the network. Therefore, this paper proposes a cache replacement policy suitable for situations in which popularity is constantly changing, taking into account the actual network situation. In order to evaluate the performance of the proposed algorithm, we experimented in an environment where the popularity of content is constantly changing, and confirmed that we are superior to the existing replacement policy through comparing hit rates and analyzing server load.

• Biomedical Science Letters
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• v.28 no.2
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• pp.59-66
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• 2022

The Cyr61/CTGF/NOV (CCN) family is dynamically expressed in various tissues, including the nervous system, from the prenatal period to adulthood. However, major studies have been conducted only in limited fields, such as the cardiovascular and muscular systems, skeletal development, and cancer. In addition, although the CCN family is a secretory protein, very few studies have described its mechanism of secretion. Recently, it has been suggested that overexpression of CCN3 or intracellular accumulation due to problems in the secretory pathway can inhibit neuronal axonal growth. In this review, we have briefly summarized the structure and characteristics of the CCN family and its related diseases, with particular emphasis on the secretory mechanism and modifiers of the CCN family, newly identified in the nervous system.

• Atmosphere
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• v.26 no.2
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• pp.243-256
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• 2016

Total number concentration of aerosols larger than 10 nm ($N_{CN10}$), 3 nm ($N_{CN3}$), and cloud condensation nuclei ($N_{CCN}$) were measured during four different ship cruises over the Yellow Sea. Average values of $N_{CN10}$ and $N_{CCN}$ at 0.6% supersaturation were 6914 and $3353cm^{-3}$, respectively, and the minimum value of $N_{CN10}$ was $2000cm^{-3}$, suggesting significant anthropogenic influence even at relatively clean marine environment. Although $N_{CN10}$ and $N_{CN3}$ increased near the coast due to anthropogenic influence, $N_{CCN}$ was relatively constant and therefore $N_{CCN}/N_{CN10}$ ratio tended to decrease, suggesting that coastal aerosols were relatively less hygroscopic. In general $N_{CN10}$, $N_{CN3}$, and $N_{CCN}$ during the cruises seemed to be significantly influenced by wet scavenging effects (e.g. fog) and boundary layer height variation. Only one new particle formation (NPF) event was observed during the measurement period. Interestingly, the NPF event occurred during a dust storm event and spatial scale of the NPF event was estimated to be larger than 100 km. These results demonstrate that aerosol and CCN concentration over the Yellow Sea can vary due to various different factors.

• Atmosphere
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• v.22 no.1
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• pp.87-96
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• 2012

Aerosol number concentration ($N_{CN}$), size distribution and cloud condensation nuclei (CCN) concentration ($N_{CCN}$) were measured during 16-21 August 2008 at Daegwallyeong (DG) located in the eastern rural region of the Korean Peninsula. In the very next week (22-29 August 2008) the same aerosol properties were measured at Yeongjong Island (YJ) in the Yellow Sea. $N_{CN}$ for all 3 size cuts (above 3, 6 and 10 nm) was significantly higher at DG than YJ, but $N_{CCN}$ was significantly lower at the former and resulted in the $N_{CCN}/N_{CN}$ ratio more than twice higher at YJ ($0.94{\pm}0.09$ vs. $0.35{\pm}0.15$ at 0.53% supersaturation). The geometric mean diameter at DG, $53{\pm}15nm$, was much smaller than that at YJ, $91{\pm}6nm$, due to the particle formation events that were likely to have occurred continuously at DG. For given mean diameter, aerosols were more likely to act as CCN at YG compared to those at DG.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38A no.3
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• pp.277-288
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• 2013

3GPP LTE-Advanced (Third Generation Partnership Project Long Term Evolution-Advanced) as a next generation mobile communication standard introduced small base stations such as femto cells or pico cells, and D2D (Device-to-Device) communications between mobiles in the proximity in order to satisfy the needs of rapidly growing wireless data traffic. A diverse range of topics has been studied to solve various interference situations which may occur within a single cell. In particular, an introduction of a small base station along with D2D communication raises important issues of how to increase the channel capacity and frequency efficiency in HetNets (Heterogeneous Networks). To this end, we propose in this paper methods to manage the interference between the macro cell and other small cells in the HetNet to improve the frequency efficiency. The proposed CCN (Cluster Coordinator Node)-assisted ICI (Inter-Cell Interference) avoidance methods exploit the CCN to control the interference in HetNet comprising of an MeNB (Macro enhanced Node-B) and a large number of small cells. A CCN which is located at the center of a number of small cells serves to avoid the interference between macro cell and small cells. We propose methods of resource allocation to avoid ICI for user equipments within the CCN coverage, and evaluate their performance through system-level computer simulations.

• The Journal of the Convergence on Culture Technology
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• v.5 no.1
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• pp.429-434
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• 2019

There are several high technologies applied to the driving cars such as self-driving car and connected car for safe and convenient driving. VANET provides useful information such as route selection and gas price by communicating nearby cars and RSUs. VANET prefers CCN rather than traditional TCP/IP stack because CCN offers inherent multicast communication for sharing traffic information as well as traditional unicast. When all participating node rebroadcasts the Interest packets in a Vehicular CCN, the network may suffer from Broadcast Storm Problem. In order to mitigate the effect of the problem and to improve the Data packet transmission, not all but some selected nodes have to rebroadcast the packet. This paper simulates car movements using SUMO and evaluates data transmission performance using ns-3. According to the simulation results, when some selected nodes rebroadcast the Interest packets, the transmission performance improves 10% to 25% depending on the number of requesting nodes.

• The Journal of the Convergence on Culture Technology
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• v.6 no.1
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• pp.495-500
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• 2020

VANET (Vehicular Ad Hoc Network), an example of an ad hoc vehicular networks, becomes one of the popular research areas together with the self-driving cars and the connected cars. In terms of the VANET implementation, the traditional TCP/IP protocol stack could be applied to VANET. Recently, CCN (Content Centric Networking) shows better possibility to apply to VANET, called VCCN (VANET over CCN). CCN maintains several data tables including CS (Content Store) which keeps track of the currently requested content segments. When the CS becomes full and new content should be stored in CS, a replacement algorithm is needed. This paper compares and contrasts four replacement algorithms. In addition, it analyzes the transmission characteristics in diverse network conditions. According to the simulation results, LRU replacement algorithm shows better performances than the remaining three algorithms. In addition, even the size of CS is small, the network maintains a reasonable transmission performance. As the CS size becomes larger, the transmission rate increases proportionally. The transmission performance decreases when the network is crowded as well as the number of transmission hops becomes large.