• Advances in nano research
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• v.13 no.6
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• pp.575-585
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• 2022

Due to its biofilm formation and colonization of the osteocyte-lacuno canalicular network (OLCN), Staphylococcus aureus (S.aureus) implant-associated bone infection (SIABI) is difficult to cure thoroughly, and may occur recurrently subsequently after a long period dormant. It is essential to explore an alternative therapeutic strategy that can eradicate the pathogens in the infected foci. To address this, the polymethylmethacrylate (PMMA) bone cement and Fe3O4 nanoparticles compound cylinder were developed as implants based on their size and mechanical properties for the alternative magnetic field (AMF) induced thermal ablation, The PMMA mixed with optimized 2% Fe₃O₄ nanoparticles showed an excellent antibacterial efficacy in vitro. It was evaluated by the CFU, CT scan and histopathological staining on a rabbit 1-stage transtibial screw model. The results showed that on week 7, the CFU of infected soft tissue and implants, and the white blood cells (WBCs) of the PMMA+2% Fe₃O₄+AMF group decreased significantly from their controls (p<0.05). PMMA+2% Fe₃O₄+AMF group did not observe bone resorption, periosteal reaction, and infectious reactive bone formation by CT images. Further histopathological H&E and Gram Staining confirmed there was no obvious inflammatory cell infiltration, neither pathogens residue nor noticeably burn damage around the infected screw channel in the PMMA+2% Fe₃O₄+AMF group. Further investigation of nanoparticle distributions in bone marrow medullary and vital organs of heart, liver, spleen, lung, and kidney. There were no significantly extra Fe₃O₄ nanoparticles were observed in the medullary cavity and all vital organs either. In the current study, PMMA+2% Fe₃O₄+AMF shows promising therapeutic potential for SIABI by providing excellent mechanical support, and promising efficacy of eradicating the residual pathogenic bacteria in bone infected lesions.

• Korean small business review
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• v.41 no.1
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• pp.1-28
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• 2019

The purpose of this study is to contribute to the revitalization of the 6th industry by presenting suggestions on how to utilize agricultural food mobile SNS and how to purchase intention. In this study, the mobile SNS, which is rapidly emerging as a new marketing channel, was applied to the agricultural and food sector to conduct a empirical analysis. First of all, the characteristics of agricultural food-related mobile SNS that affect the purchasing intent of agricultural food were derived, and the indirect effects of consumer attitudes were analyzed in relation to the perceived characteristics of the mobile SNS for the agricultural food and the purchase intention. First, information quality and ease of access have a significant effect on cognitive attitude (+), and playfulness, information quality, ease of access have a significant effect on emotional attitude (+), and playfulness, interactivity have a significant effect on an acting attitude (+). Second, information quality, accessibility, and playfulness have a significant effect on purchase intention (+), and the quality of information has the greatest influence. Third, it was analyzed that information quality, interactivity, ease of accessibility, and playfulness have an indirect effect of consumer attitude in the path of purchase through consumer attitude. From the results of this study, it was confirmed that efforts to improve the quality of information in the case of mobile SNS related to agricultural and food products are needed first, that to improve the purchasing intent, we need to establish a mobile SNS operating strategy and marketing strategy for enhance consumer attitudes in a favorable. On the other hand, related education and system cooperation methods should be prepared to enable agricultural and food companies to use mobile SNS as a marketing tool.

• Journal of Digital Convergence
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• v.14 no.5
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• pp.11-19
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• 2016

SNS users are continuously increasing and SNS is emerging as a major PR channel of government. In particular, SNS can be a useful tool, but also the challenges for risk communication. This study is examined how nuclear regulatory organizations' SNS management and visitors' responses to the facebook pages in Korea and U.S.. Results indicated that both organizations frequently used information-oriented posting. Concerning the types of PR, NSSC tended to mainly use 'Relationship-Management PR', NRC mainly use 'Image PR.' In addition, our analyses on visitors' responses showed that visitors usually in response to participational and visual(ex. video, card news) typed contents. Based on its' results, this study provides practical suggestions for government's future SNS management strategies.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.4
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• pp.105-117
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• 2015

In this paper, we consider 19 cells with the two tiers for polar-rectangular coordinates (PRCs) and provide the cell edge performance of cellular networks based on distance from cell center i.e., BS (base station). When FFR is applied(or adopted) to cell edge, it is expected that BS cooperation, or a coordinated multipoint (CoMP) multiple access strategy will further improve the system performance. We proposed a new method to evaluate the sum rate capacity of the MIMO DC of multicell system. We improve the performance of cell edge users for intercell interference cancelation in cooperative downlink multicell systems. Simulation results show that the proposed scheme outperforms the reference schemes, in terms of cell edge SINR (signal-to-interference-noise ratio) with a minimal impact on the network path loss exponent. We show 13 dB improvements in cell-edge SINR by using reuse of three relative to reuse of one. BS cooperation has been proposed to mitigate the cell edge effect.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.8
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• pp.3529-3550
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• 2016

In heterogeneous networks (HetNets), energy saving is vital for a sustainable network development. Many techniques, such as spectrum allocation, network planning, etc., are used to improve the network energy efficiency (EE). In this paper, micro BSs utilizing cell range expansion (CRE) and spectrum allocation are considered in multi-channel heterogeneous networks to improve EE. Hotspot region is assumed to be covered by micro BSs which can ensure that the hotspot capacity is greater than the average demand of hotspot users. The expressions of network energy efficiency are derived under shared, orthogonal and hybrid subchannel allocation schemes, respectively. Particle swarm optimization (PSO) algorithm is used to solve the optimal ratio of subchannel allocation in orthogonal and hybrid schemes. Based on the results of the optimal analysis, we propose three service control strategies on the basis of large-scale user behaviors, i.e., adjust micro cell rang expansion (AmCRE), adjust micro BSs density (AmBD) and adjust micro BSs transmit power (AmBTP). Both theoretical and simulation results show that using shared subchannel allocation scheme in AmBD strategies can obtain maximal EE with a very small area ratio. Using orthogonal subchannel allocation scheme in AmCRE strategies can obtain maximal EE when area ratio is larger. Using hybrid subchannel allocation scheme in AmCRE strategies can obtain maximal EE when area ratio is large enough. No matter which service control strategy is used, orthogonal spectrum scheme can obtain the maximal hotspot user rates.

• Journal of Contemporary Eastern Asia
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• v.19 no.1
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• pp.43-58
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• 2020

This study examines media used for information in the East Asian countries of China, Japan, South Korea, Taiwan, and Singapore, using data from the World Values Survey. The sharing of Confucian culture may lead to a uniform media structure across these nations. Another possibility is technological determinism, which would also lead to similarity across nations. However, it is possible that countries are at different stages of technology development and will eventually become more similar. An opposing notion is that differences in other values among nations predict digital media use. To examine the evidence considering these possibilities, we factor analyze each population's use of nine traditional and digital media to see how similar the structures are. What results is a three-dimensional solution for four out of five countries, except Singapore, which has a more simple two-dimensional structure. Analysts regard Singapore as the most digitally connected society, which raises the question as to whether it is higher on a technological development trajectory, to which other countries may transition. Perhaps a more simple media use structure is an adaptation to increasing information load. As well, as mobile devices have become a primary means of accessing the range of traditional and social media, it may have an expanded role in reducing media channel entropy. In terms of frequency of media use, Singapore is highest, while China is the lowest. Singapore stands out in high mobile use, and China for low Internet use. There appear to be developmental differences across the nations. Regressions on Internet use for 18 values indices find different values predictors in the East Asian countries, ruling out Confucianism as producing similar media patterns.

• Journal of Distribution Science
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• v.16 no.12
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• pp.57-68
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• 2018

Purpose - The development of technologies lead the volume of sale on online market increase but an off-line shopping center is still a core component in the omni-channel strategy. It is generally thought that high-level retailtainment on brick and mortar store affects purchase intentions positively, but some previous studies dispute that and have reported that retailtainment does not affect purchase intentions. So we have studied the additional factors' effect - the nature of purchase and utility - with retailtainment. Research design, data, and methodology - There are 8 treatment groups which were assigned by the method of retailtainment (high vs. low), nature of purchase (essential vs. non-essential), and utility (acquisition vs. transaction). A total of 240 subjects (office workers = 163, 68%; undergraduates = 77, 32%; average age = 30s; female = 39%) were divided into groups and exposed to one of the eight scenarios. Participant's purchase intention was the dependent, and ANOVA and L-matrix were used to analyze for main and interactive effects between factors. Results - First, the main effect and interactive effect between retailtainment and the nature of purchase are significant. We also found that the contrast between essential and non-essential at low-level retailtainment is higher than that of high-level retailtainment. Second, in the case of retailtainment and utility, transaction utility under high-level retailtainment affects purchase intentions positively. Third, between the nature of the purchase and utility, the main effect of the nature of purchase and the interactive effect is significant, but the main effect of utility is not significant. In the case of non-essential goods, the purchase intention was high when transaction utility was provided but in the case of essential goods, acquisition utility increased purchase intentions. Finally, when transaction utility is given, purchase intentions of essential goods increase under low retailtainment, and the purchase intentions of non-essential goods increase under high retailtainment. Conclusions - When customers buy essential goods, discounts decrease purchase intentions. During the season for bargain sales, purchase intentions increase when retailtainment of essential goods is low, and retailtainment of non-essential goods is high.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.2
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• pp.700-713
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• 2015

It is critical to design energy-efficient routing protocols for battery-limited mobile ad hoc networks, especially in which the energy-consuming MIMO techniques are employed. However, there are several challenges in such a design: first, it is difficult to characterize the energy consumption of a MIMO-based link; second, without a careful design, the broadcasted RREP packets, which are used in most energy-efficient routing protocols, could flood over the networks, and the destination node cannot decide when to reply the communication request; third, due to node mobility and persistent channel degradation, the selected route paths would break down frequently and hence the protocol overhead is increased further. To address these issues, in this paper, a novel Greedy Energy-Efficient Routing (GEER) protocol is proposed: (a) a generalized energy consumption model for the MIMO-based link, considering the trade-off between multiplexing and diversity gains, is derived to minimize link energy consumption and obtain the optimal transmit model; (b) a simple greedy route discovery algorithm and a novel adaptive reply strategy are adopted to speed up path setup with a reduced establishment overhead; (c) a lightweight route maintenance mechanism is introduced to adaptively rebuild the broken links. Extensive simulation results show that, in comparison with the conventional solutions, the proposed GEER protocol can significantly reduce the energy consumption by up to 68.74%.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39B no.11
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• pp.790-802
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• 2014

In cognitive radio technology, secondary users can determine the absence of PU by periodic sensing operation and cooperative sensing between SUs yields a significant sensing performance improvement. However, there exists a trade off between the gains in terms of probability of detection of the primary users and the costs of false alarm probability. Therefore, the cooperation group must maintain the suitable size. And secondary users should sense not only the currently using channels and but also other candidates channel to switch in accordance with sudden appearance of the primary user. In this paper, we propose an effective group cooperative sensing algorithm in distributed network situations that is considering both of inband and outband sensing using evolutionary game theory. We derived that the strategy group of secondary users converges to an ESS(Evolutionary sable state). Using a learning algorithm, each secondary user can converge to the ESS without the exchange of information to each other.

• Journal of Information Technology Services
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• v.14 no.2
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• pp.315-335
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• 2015

The New Way of Working (NWOW) is changing the world in which we work today. The principles of NWOW are based on freedom of time and place to work, and steering on output (results) instead of input (presence). As NWOW is a relatively new phenomenon, research on the effect of NWOW on knowledge sharing in organizations is scarce. In this research two multiple-case studies were performed to investigate the effect of the New Way of Working on knowledge. In the first study (A) different knowledge sharing scenarios were used at organizations that were in the process of implementing NWOW. This provided the opportunity to compare the sharing of knowledge between 'NWOW workers' and employees that still worked in the traditional way (non-NWOW workers). In total 216 scenario results were evaluated to determine differences in channel choice between the traditional and new work environment. For the second study (B) a Knowledge Sharing Framework was developed, based on the theories of Nonaka and Alavi & Leidner. This framework was used to determine the type of knowledge shared, e.g. tacit or explicit knowledge, in 84 situations. Additionally, to measure the level of NWOW adoption, a NWOW Analysis Monitor was used. The results show that NWOW workers use more different communication channels than traditional workers. When knowledge workers become more mobile, they will exchange knowledge less explicit (codified) and more tacit (personalized), use less face-to-face communication, but more video calls and e-mail. The adoption of the principles of NWOW seems to have a balancing effect on the knowledge that is shared in a tacit and explicit way, which in the view of Scheepers et al. is an effective knowledge sharing strategy. The research results show organizations need to realize that the New World of Working is affecting the way knowledge is shared. Missing out on this development may result in the loss of important knowledge and impact the operation of organizations.