• Journal of the Institute of Electronics Engineers of Korea TC
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• v.47 no.7
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• pp.72-79
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• 2010

Device-to-device(D2D) links which share resources in a cellular network present a challenge in radio resource management due to the potentially severe interference they may cause to the cellular network. In this paper, a resource allocation scheme based on subset reuse methods is proposed to minimize the interference from the D2D links. We consider an adaptive group-wise subset reuse method to enhance the efficiency of frequency resource allocation for cellular and D2D links. A power optimization scheme is also proposed for D2D links if cellular links are interfered by adjacent D2D transmissions. The computer simulation results show that performance gain is obtained in link SINR, and total cell throughput increases as nearby traffic becomes more dominant.

• Journal of dental hygiene science
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• v.22 no.3
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• pp.164-170
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• 2022

Background: When cells are damaged by nicotine, cellular senescence due to oxidative stress accelerates. In addition, stress-induced inflammatory response and cellular senescence cause the accumulation of damaged organelles in cells, and autophagy appears to remove them. Conversely, when autophagy is reduced, harmful cell components accumulate, and aging is accelerated. This study aimed to determine the association between nicotine-induced cellular senescence and autophagy expression patterns in human gingival fibroblasts. Methods: Cells were treated with various concentrations of nicotine (0, 0.1, 0.5, 1, 2, and 5 mM) and 10 nM rapamycin was added to 1 mM nicotine to investigate the relationship between autophagy and cellular senescence. Cell viability was confirmed using WST-8 and the degree of cellular senescence was measured by SA-β-gal staining. The expression of the inflammatory proteins (COX-2 and iNOS) and autophagy markers (LC3-II, p62, and Beclin-1) was analyzed by western blotting. Results: The cell viability tended to decrease in a concentration-dependent manner. COX-2 showed no concentration-dependent expression and iNOS increased in the 0.5 mM nicotine treated group. The degree of cellular senescence was the highest in the 1 mM nicotine treatment group. In the group treated with rapamycin and nicotine, the conversion ratio of LC3-II to LC3-I was the highest, that of p62 was the lowest, and the level of Beclin-1 proteins was significantly increased. Furthermore, the degree of cellular senescence was reduced in the group in which rapamycin was added to nicotine compared to that in the group treated with nicotine alone. Conclusion: This study provides evidence that autophagy activated in an aging environment reduces cellular senescence to a certain some extent.

• IEIE Transactions on Smart Processing and Computing
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• v.6 no.3
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• pp.151-157
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• 2017

Management optimization is very important in tourism, especially when it is related to productivity. One of the problems in management optimization is tour guide assignment. Well-arranged tour guide assignment will increase productivity while maintaining service quality. A cellular genetic algorithm is one of the methods that can be used to solve this problem. Furthermore, previous study has shown that a cellular dimension increase can lead to promising benefits for certain problems. The objective of this research is to give a clear understanding of the advantages of increasing cellular dimensionality on the tour guide assignment problem by using a cellular genetic algorithm.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.8
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• pp.3435-3454
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• 2016

Device-to-device (D2D) communication is a potential solution to the incessant increase in data traffic on cellular networks. The greatest problem is how to control the interference between D2D users and cellular mobile users, and between D2D users themselves. This paper proposes a solution for this issue by putting the full control privilege in cellular network using the software-defined networking (SDN) concept. A software virtual switch called Open vSwitch and several components are integrated into mobile devices for data forwarding and radio resource mapping, whereas the control functions are executed in the cellular network via a SDN controller. This allows the network to assign radio resources for D2D communication directly, thus reducing interference. This solution also brings out many benefits, including resource efficiency, energy saving, topology flexibility, etc. The advantages and disadvantages of this architecture are analyzed by both a mathematical method and a simple implementation. The result shows that implementation of this solution in the next generation of cellular networks is feasible.

• Journal of Families and Better Life
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• v.24 no.5 s.83
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• pp.101-112
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• 2006

This study examined factors related to the motivation for the uses of cellular phones and the relationship between motivation for cellular phone use and parent-child communication among middle school students. A total of 223 questionnaires were submitted and analyzed. The characteristics of motive structure of the middle school students were found as recreation, time management, information-seeking, reassurance and fashion/showing off. Among those motivations, these middle school students examined here were found to use cellular phones in similar ways to how conventional telephone is used such as work/instrumental reasons and socializing/entertaining. The motivations showed a significant association with the level of parent-child communication. Information-seeking and time management motivation were positively related with an open communication level while fashion/showing off and recreation were negatively related with an open communication level.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1996.04a
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• pp.324-327
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• 1996

In this paper, the affecting factors of the access demand for the cellular service are derived, and the access demand function of the cellular service is estimated. The results obtained in this study are as follows: First, the price (access charge) and the income elasticities of cellular services there exists a network externality in cellular communication services. Third, the technological capability of the service provider has played an essential role in expanding the size of subscribers. Fourth, the access demand of cellular communication service is not sensitive to the usage charge. According to the above results, it can be inferred that if the access charge is lowered, the number if subscribers will increase to the critical mass, and then the cellular communication market will grow up to a saturation point naturally.

• Journal of Multimedia Information System
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• v.3 no.4
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• pp.135-140
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• 2016

To improve the throughput of Device-to-Device (D2D) communication, we focus on the scenario where D2D pair can reuse multi-channel of cellular communication. However, as sharing same channel with cellular communication can cause interference between D2D communication and cellular communication, a proper interference management is needed. In this paper, we propose interference-based channel allocation to select the channels to be used by D2D communication and a solution from game theory perspective to optimize the D2D communication throughput under multi-channel as well as guarantee the interference from it to cellular network. The simulation results verify the stability of the proposed method.

• Journal of Korea Multimedia Society
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• v.6 no.4
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• pp.610-619
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• 2003

This paper presents a concept of cellular automata and a modular exponentiation algorithm and implementation of a basic EIGamal encryption by using cellular automata. Nowadays most of modular exponentiation algorithms are implemented by a linear feedback shift register(LFSR), but its structure has disadvantage which is difficult to implement an operation scheme when the basis is changed frequently The proposed algorithm based on a cellular automata in this paper can overcome this shortcomings, and can be effectively applied to the modular exponentiation algorithm by using the characteristic of the parallelism and flexibility of cellular automata. We also propose a new fast multiplier algorithm using the normal basis representation. A new multiplier algorithm based on normal basis is quite fast than the conventional algorithms using standard basis. This application is also applicable to construct operational structures such as multiplication, exponentiation and inversion algorithm for EIGamal cryptosystem.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.4
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• pp.1841-1865
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• 2017

This paper proposes a new interference mitigation scheme for device-to-device (D2D) communications underlaying a cellular network. The object of the proposed scheme is to determine the number of data streams, a precoding matrix, and a decoding matrix of D2D networks so as to maximize the system capacity given the number of data streams of a cellular network while satisfying the constraint of the inter-system interference from D2D networks to the cellular network. Unlike existing interference mitigation schemes based on the interference alignment technique, the proposed scheme operates properly regardless of the number of data streams of a cellular network and moreover it does not require changing the precoding and decoding matrices of a cellular network. The simulation results demonstrate that the proposed scheme significantly increases the system capacity by mitigating the intra- and inter-system interference.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.04a
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• pp.825-830
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• 1999

The purpose of this study is to improve overall performance of prefoamed lightweight cellular concrete for On-Dol system floor. This study includes 4 sections as follows. \circled1 Analysis of the structural characteristics of On-Dol System focusing on the lightweight cellular concrete insulation layer. \circled2 Establishment of the mixing design equations. \circled3 Development of some admixtures used with foaming agent. \circled4 Improvement of the equipment for onsite production. This study has proven that, compared with the current existing one, the newly developed lightweight cellular concrete has been reduced the usage of cement by 20% and the cracks caused by cement drying shrinkage up to 80% but has shown the increased compression strength by 20% at 7 days curing period. The volume contraction of freshly prepared cellular concrete by the loss of foam was hardly found in newly developed lightweight cellular concrete.