• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1993.10a
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• pp.5-18
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• 1993

This paper reports the recent trends in active vibration control in Japan, especially, based on papers selected in the Proceedings of First International Conference on Motion and Vibration Control (1st MOVIC) held at Yokohama, Japan on Sept.7-11, 1992. Firstly, it classifiers vibration control methods and vibration controllers, especially active dynamic absorbers which are widely used in mechanical and civil engineering. Secondly, it covers basic problems in the control of vibration of flexible structures such as formulating a reduced-order model required for designing vibration controller, proper arranging of sensors and actuators, and preventing of spillover instability. Finally, the practical use of control theories such as LQ control theory, $H^{\infty}$ control theory, neural network theory, and other topics are discussed..

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.11 no.4
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• pp.19-38
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• 2007

Graph theory is becoming increasingly significant as it is applied of mathematics, science and technology. It is being actively used in fields as varied as biochemistry(genomics), electrical engineering(communication networks and coding theory), computer science(algorithms and computation) and operations research(scheduling). The powerful results in other areas of pure mathematics. Rhis paper, besides giving a general outlook of these facts, includes new graph theoretical proofs of Fermat's Little Theorem and the Nielson-Schreier Theorem. New applications to DNA sequencing (the SNP assembly problem) and computer network security (worm propagation) using minimum vertex covers in graphs are discussed. We also show how to apply edge coloring and matching in graphs for scheduling (the timetabling problem) and vertex coloring in graphs for map coloring and the assignment of frequencies in GSM mobile phone networks. Finally, we revisit the classical problem of finding re-entrant knight's tours on a chessboard using Hamiltonian circuits in graphs.

• Journal of Public Diplomacy
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• v.1 no.2
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• pp.49-74
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• 2021

In this paper, I applied grounded theory in exploring how Twitter became the battlefield for China's public diplomacy campaign. China's new move to global social media platforms, such as Twitter and Facebook, has been a controversial strategy in public diplomacy. This study analyzes Chinese Foreign Spokesperson Zhao Lijian's Twitter posts and comments. It models China's recent diplomatic move to Twitter as a "war of words" model, with features including "leadership," "polarization," and "aggression," while exerting possible effects as "resistance," "hatred," and "sarcasm" to the global community. Our findings show that by failing to gage public opinion and promote the country's positive image, China's current digital diplomacy strategy reflected by Zhao Lijian's tweets has instead constructed a polarized political public sphere, contradictory to the country's promoted "shared human destiny." The "war of words" model extends our understanding of China's new digital diplomacy move as a hybrid of state propaganda and self-performance. Such a strategy could spread hate speech and accelerate political polarization in cyberspace, despite improvements to China's homogenous network building on Twitter.

• Asia pacific journal of information systems
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• v.30 no.4
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• pp.695-718
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• 2020

Based on the Construal Level Theory, we aim to study a most favorable fit among the advertising model, media type, and message construals, which are important factors in an advertisement. A two (social distance of the ad model in an ad: distal (low similarity) vs proximal (high similarity) by two (social distance of a media type: distal (portal) vs. proximal (SNS)) by two (message construal: abstract vs concrete) laboratory experiment was conducted to examine attitude changes on ad messages. The results show that abstract messages were more effective in attitude toward advertisement and purchase intention under the distal social distance (i.e. advertising model in low-similarity and portal media type) while concrete messages were so under the proximal social distance and SNS media type.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.10
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• pp.2281-2287
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• 2013

Network Coding(NC) is a new paradigm for network communication. In network coding, intermediate nodes create new packets by algebraically combining ingress packets and send it to its neighbor node by broadcast manner. Network Coding has rapidly emerged as a major research area in information theory due to its wide applicability to communication through real networks. Network coding is expected to improve throughput and channel efficiency in the wireless multi-hop network. Prior researches have been carried out to employ network coding to wireless ad-hoc network. In our study, intermediate nodes identify one-hop bidirectional flows for network coding decision. We expect that the proposed scheme shall improve decoding success rate of network coded packet. From the simulation, the proposed network coding scheme achieved better performance in terms of coding gain and packet delivery rate than traditional network coding scheme.

• Science of Emotion and Sensibility
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• v.21 no.3
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• pp.83-102
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• 2018

The process model of emotion regulation suggests that cognitive reappraisal and expressive suppression engage at different time points in the regulation process. Although multiple brain regions and networks have been identified for each strategy, no articles have explored changes in network characteristics or network connectivity over time. The present study examined (a) the whole-brain network and six other resting-state networks, (b) their modularity and global efficiency, which is an index of the efficiency of information exchange across the network, (c) the degree and betweenness centrality for 160 brain regions to identify the hub nodes with the most control over the entire network, and (d) the intra-network and inter-network functional connectivity (FC). Such investigations were performed using a traditional large-scale FC analysis and a relatively recent sliding window correlation analysis. The results showed that the right inferior orbitofrontal cortex was the hub region of the whole-brain network for both strategies. The present findings of temporally altering functional activity of the networks revealed that the default mode network (DMN) activated at the early stage of reappraisal, followed by the task-positive networks (cingulo-opercular network and fronto-parietal network), emotion-processing networks (the cerebellar network and DMN), and sensorimotor network (SMN) that activated at the early stage of suppression, followed by the greater recruitment of task-positive networks and their functional connection with the emotional response-related networks (SMN and occipital network). This is the first study that provides neuroimaging evidence supporting the process model of emotion regulation by revealing the temporally varying network efficiency and intra- and inter-network functional connections of reappraisal and suppression.

• Journal of KIISE:Information Networking
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• v.37 no.3
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• pp.167-174
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• 2010

Recently the distributed topology control algorithm for constructing the Recrystallization Topology in the unstructured peer-to-peer network was proposed. In this paper, we prove that such a hierarchical topology is a scale-free power-law network. We present a model of a construction process of the distributed protocol, and analyze it based on a mean-field approximation and the continuum theory, so that we show that the constructed Recrystallization Topology is a scale-free network. In the proposed model, all nodes are born with some initial attractiveness and the system incorporates the rewiring of some links at every time step. Some old links are removed with the anti-preferential probability, and some new links are added with preferential probability. In other words, according to the distributed algorithm, each node makes connections to the more-preferential nodes having higher hit-ratio than other nodes, while it disconnects the anti-preferential nodes having lesser hit-ratio. This gives a realistic description of the local processes forming the recrystallization topology in unstructured peer-to-peer network. We calculate analytically the degree distribution. The analytic result indicates that the constructed network is a scale-free network, of which the scaling exponent is 3.

• Journal of Science and Technology Studies
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• v.9 no.1
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• pp.89-127
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• 2009

The Korean Astronaut Project(KAP) aims to make the first Korean astronaut fly and take part in space activities in the International Space Station(ISS) in April 2008. KAP was on the purpose of studying the requirement to master manned space technologies as part of the long-term basic plan for national space development. However, people criticized that Ms. Yi was a 'space tourist' not an 'astronaut' because KAP was a program for pride, prestige in 21c's new space race, not specifically science and technology. The government emphasized that Yi carried out her 15 experiments in ISS very competently. In contrast people devaluated Yi's space experiments as below the level, though some of them are enough meaningful to be published on SCI journals. Why did the government fail to make people take Ms. Yi as an astronaut? I answer to this question using the notion of "Network Analysis" based on Actor-Network Theory(ANT).

• Korean journal of communication and information
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• v.67
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• pp.62-87
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• 2014

The purpose of this study is to understand the social and cultural implication of the activities of taking 'selfies' and the use of Social Network Service(SNS)s through the personal story of a 20s female researcher. She analyzes her own digital photography activities based on the experience of the use of Cyworld photo albums for three years and the use of pictures in iPhone album for fifteen months. The other researcher(40s male) cooperates to answer the questions about how to understand the digital photography activities. We understand the digital photography activities including digital cameras, social network services and smart phones as acts of personal identity configuration and acts of making the personal documentary. As a result, digital photos are used more for archive purpose rather than for document purpose. Also, we found that the digital photography activities can be understood as the interactions between human and non-human actors in the perspective of Actor-Network Theory (ANT).

• Journal of the Korean Society for information Management
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• v.35 no.1
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• pp.157-182
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• 2018

As data management and processing techniques have been developed rapidly in the era of big data, nowadays a lot of business companies and researchers have been interested in long tail data which were ignored in the past. This study proposes methods for generating and controlling a network of technical terms based on text mining technique to enhance data utilization in the distribution of long tail theory. Especially, an edit distance technique of text mining has given us efficient methods to automatically create an interlinking network of technical terms in the scholarly field. We have also used linked open data system to gather experimental data to improve data utilization and proposed effective methods to use data of LOD systems and algorithm to recognize patterns of terms. Finally, the performance evaluation test of the network of technical terms has shown that the proposed methods were useful to enhance the rate of data utilization.