• KIPS Transactions on Computer and Communication Systems
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• v.4 no.1
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• pp.5-10
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• 2015

D2D (Device-to-Device) communication underlaying LTE-advanced networks is a promising technology to improve the system capacity and spectral efficiency. By sharing the same radio resources with cellular user equipments, D2D communications can significantly enhance the overall spectral efficiency. However, it may cause interference between D2D link and cellular link. Careful resource allocation and interference coordination between cellular and D2D communications are very important and need to be properly handled. This paper proposes a radio resource allocation scheme based on FFFR (Flexible Fractional Frequency Reuse) for D2D communication underlaying cellular networks. The base station selects randomly resource blocks assigned to cellular users, and reuses them for a D2D pair. Through simulations, we have confirmed that the proposed scheme improves the system throughput, reduces the computational complexity, and mitigates the interference of D2D link and cellular link.

• The Journal of Korean Medicine
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• v.20 no.2
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• pp.88-97
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• 1999

To characterize the effects of Gilgyung-Tang(GGT) on cellular proliferation and viability of normal lung fibroblast cells, we examined the cell cycle progression and cell cycle-related gene expression in T3891 using a flow cytometry and a quantitative RT-PCR analysis. 1. The significant surpression effect of cellular proliferations of GGT was observed in proportion to a certain concentration and time. 2. GGT was identified to induce apoptotic death of damaged cells by treatment with a DNA-damage agent and etoposide, while it stimulated the recovery of cellular viability of normal cells. 3 The significant reductions of mRNA expression of PCAN, c-Fos treated by GGT were observed. 4. The significant inductions of mRNA expression of p53, CDKN1. Gadd45 treated by GGT were observed. 5. The apoptosis caused by the reduction of Bcl-2 genes was significant and the Bax genes were increased. but the amount of Fas genes were not changed. These results strongly suggest that GGT triggers arrest of the cell cycle at G1 phase, and thus causes an inhibition of cellular proliferation of human normal lung cells through the transcriptional up-regulation of cell cycle inhibitory genes and down-regulation of induction of cell cycle stimulating genes respectably.

• Journal of Korea Multimedia Society
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• v.13 no.9
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• pp.1329-1336
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• 2010

Cellular Automata is a discrete dynamical system which natural phenomena may be specified completely in terms of local relation, can increase and decrease the difference of luminance locally according to transition rule by keeping the characteristic of target image. In this paper, we propose a noise reduction method by keeping the characteristic using transition rule of Cellular Automata, also we propose methods of effective transition rule, the selection of parameters, the selection of number of neighborhood pixels. For uniform distribution noise, Gaussian noise, impulse noise, we do an experiment on adaptive state using different mathematical operations and compare its results. It was confirmed that the proposed transition rule is based on fast convergence speed and has stabile results.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.4
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• pp.1884-1903
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• 2019

Device-to-Device (D2D) communications can provide proximity based services in the future 5G cellular networks. It allows short range communication in a limited area with the advantages of power saving, high data rate and traffic offloading. However, D2D communications may reuse the licensed channels with cellular communications and potentially result in critical interferences to nearby devices. To control the interference and improve network throughput in overlaid D2D cellular networks, a novel channel assignment approach is proposed in this paper. First, we characterize the performance of devices by using Poisson point process model. Then, we convert the throughput maximization problem into an optimal spectrum allocation problem with signal to interference plus noise ratio constraints and solve it, i.e., assigning appropriate fractions of channels to cellular communications and D2D communications. In order to mitigate the interferences between D2D devices, a cluster-based multi-channel assignment algorithm is proposed. The algorithm first cluster D2D communications into clusters to reduce the problem scale. After that, a multi-channel assignment algorithm is proposed to mitigate critical interferences among nearby devices for each D2D cluster individually. The simulation analysis conforms that the proposed algorithm can greatly increase system throughput.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1994.04a
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• pp.303-312
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• 1994

The problem of optimally allocating available communication channels in a cellular mobile system with nonuniform traffic distribution is considered. This problem is to minimize the weighted average blocking probability subject to cochannel interference constraints. We use the concept of pattern to deal with the problem more conveniently. Using Lagrangian relaxation and subgradient optimization techniques, we obtain high-quality solutions with information about their deviations from true optimal solutions. Computational experiments show that our method works very well.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.1035-1036
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• 2006

We analyzed the performance of hierarchical cellular system with multi traffic(voice traffic, data traffic). We executed the computer simulation by the various ratio of traffic generation(voice traffic, data traffic). We generated data traffic at microcell. The more voice traffic generated, the higher the block probability of data traffic became at macrocell.

• Herbal Formula Science
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• v.24 no.4
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• pp.353-365
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• 2016

Objectives : We analysed Gyejibongnyeong-hwan's compatibility principle and investigated biological activities by categorizing with molecular level, cellular level, animal level and human level based on Korean study for this formula. Methods : Gyejibongnyeong-hwan's compatibiltity principle was examined by the system of chief, deputy, assistant, and envoy. We looked into studies that presented in Korea from 1956 to 2016 about Gyejibongnyeong-hwan through Korea Institute of Oriental Medicine, Korean medicine information system (OASIS). Then classify into molecular level, cellular level, animal level and human level to analyse. Results : According to the system of chief, deputy, assistant, and envoy, chief herb is Cinnamomi Ramulus, deputy herb is Persicae Semen, assistant herb is Moutan Cortex, Paeoniae Radix, Poria, and envoy herb is Mel. Biological activities can be detected in transcription factors, enzymes, and inflammatory mediators for molecular level. For cellular level, it can be determined in human uterine endometrial cancer cell, human hepatocarcinoma cell, and human platelets. In mouse and rats for animal level, in overian cystoma, menorrhalgia, quality of life improvement in postmenopausal women, and blood stasis with motor vehicle accident for human level, biological activities was caught. Conclusions : From above results, Gyejibongnyeong-hwan is composed in line with the system of chief, deputy, assistan, and envoy. Biological activities are effective to improvement of menorrhalgia, anti-cancer, anti-oxidative, anti-inflammation, improvement of atherosclerosis, analgesic, anti-convulsion, wound healing, and improvement of liver function.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.10 s.89
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• pp.1011-1017
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• 2004

Ultra Wideband(UWB) technologies have been developed to exploit a new spectrum resource in substances and to realize ultra-high-speed communication, high precision geolocation, and other applications. The energy of UWB signal is extremely spread from near DC to a few GHz. This means that the interference between conventional narrowband systems and UWB systems is inevitable. However, the interference effects had not previously been studied from UWB wireless systems to conventional mobile wireless systems sharing the frequency bands such as Korean Cellular CDMA and WCDMA. This paper experimentally evaluates the interference from two kinds of UWB sources, namely a direct-sequence spread-spectrum CDMA(DS-CDMA) UWB source and an impulse radio UWB source, to a Cellular CDMA and WCDMA digital transmission system. The average frame error rate degradation of each system are presented. From these experimental results, the interference effects of DS-CDMA UWB source is not severe compared to the Impulse UWB.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.9
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• pp.2117-2123
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• 2014

To cope with the explosive growth of traffic which is considered as one of the most biggest threat to current mobile communication systems, various solutions such as small cell and device-to-device communication have been exploited. Directional transmission in which transmission power of base station is focused onto the direction where the mobile station is located, can be used to increase throughput of the system. In this work, we develop a system-level simulator for cellular mobile communication systems using directional transmission and adaptive interference estimation scheme for directional transmission has been proposed. By using the developed simulator, the performance of cellular mobile communication systems with directional transmission is examined. Moreover, it is shown that the overall throughput of cellular system can be improved by utilizing directional transmission.

• Molecules and Cells
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• v.44 no.11
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• pp.830-842
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• 2021

When perceiving microbe-associated molecular patterns (MAMPs) or plant-derived damage-associated molecular patterns (DAMPs), plants alter their root growth and development by displaying a reduction in the root length and the formation of root hairs and lateral roots. The exogenous application of a MAMP peptide, flg22, was shown to affect root growth by suppressing meristem activity. In addition to MAMPs, the DAMP peptide PEP1 suppresses root growth while also promoting root hair formation. However, the question of whether and how these elicitor peptides affect the development of the vascular system in the root has not been explored. The cellular receptors of PEP1, PEPR1 and PEPR2 are highly expressed in the root vascular system, while the receptors of flg22 (FLS2) and elf18 (EFR) are not. Consistent with the expression patterns of PEP1 receptors, we found that exogenously applied PEP1 has a strong impact on the division of stele cells, leading to a reduction of these cells. We also observed the alteration in the number and organization of cells that differentiate into xylem vessels. These PEP1-mediated developmental changes appear to be linked to the blockage of symplastic connections triggered by PEP1. PEP1 dramatically disrupts the symplastic movement of free green fluorescence protein (GFP) from phloem sieve elements to neighboring cells in the root meristem, leading to the deposition of a high level of callose between cells. Taken together, our first survey of PEP1-mediated vascular tissue development provides new insights into the PEP1 function as a regulator of cellular reprogramming in the Arabidopsis root vascular system.