• The Journal of the Korea institute of electronic communication sciences
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• v.5 no.3
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• pp.275-280
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• 2010

In this paper, VoIP(Voice over Internet Protocol) transmission performance for MANET(Mobile Ad-hoc Networks) is improved and analyzed with packet aggregation scheme which is aggregating some of short length packets to one large packet and sending to networks. VoIP simulator based on NS(Network Simulator)-2 is implemented and used to measure performance of VoIP traffic transmission. In this simulation, VoIP traffics are generated with parameters of some codes such as G.711, G.729A, GSM.AMR and iBLC. MOS(Mean Opinion Score), end-to-end network delay, packet loss rate and transmission bandwidth are measured. Performance improvements of 98% for MOS, 6.4times for end-to-end network delay, 32times for packet loss rate is shown as simulation results. On the other hand, transmission bandwidth is increased about maximum 10%. Finally, VoIP implementation guide for the performance with packet aggregation is suggested.

• Electronics and Telecommunications Trends
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• v.4 no.1
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• pp.35-43
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• 1989

The evolution of telecommunications has raised the profile of many segments of the network that were not previously considered important. Until recently, basic telephony existed with the extension of passive cables without any particular user network interface. In the area of data communications, the introduction of flexible packet switching has allowed the network to evolve in a far more efficient manner. To overcome such separated network problems and business needs of both users and network providers, the integrated narrowband ISDN concept is being developed in most countries for implementation in the public switched telephone network (PSTN). The targets of ISDN, in my opinion, can be explained as follows : To the user, ISDN should provide the services at any time, at any place, through any media. To the business customer using PABX or LAN applications, ISDN should introduce customized services rapidly and also, ISDN should be developed by the modular hardware and software design approach in order for new services to be introduced rapidly and effectively. Software can be also developed by non-expert local staff to cater for adopting new user's service requirements immediately. Finally, ISDN will be able to increase business chances and benefit both users and operating companies.

• Convergence Security Journal
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• v.12 no.6
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• pp.11-17
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• 2012

Network security performance evaluation is a complex and diverse system environments, a single, specific performance measurements alone performance evaluation measure itself and the meaning of the reliability of the evaluation results do not limit the number of days only. In this paper, we propose a method to measure the security features of security, QoS measurement techniques using MOS satisfaction. MOS(Mean Opinion Score) Rating specifications for network security, QoS satisfaction and how to operate the development and operational model for future customer's satisfaction for information systems that can be used to evaluate the QoS measurement/analysis be utilized in the field. Objectified in the form of standards and performance measurement system provider (supplier development) and consumers(users) all the results available so that how to develop a system. Development is the development of information security features, the performance of these two features networking capabilities and a comprehensive evaluation of a three-gaeyoungyeok Correlating performance measurement methodology. Systematic measurement environment designed using the proposed methodology of this study, when the operating system is on the satisfaction of the security, QoS can be calculated. Forward In addition, a variety of performance metrics and performance measurement methods by extending the network security system satisfaction rating upgrade by the way will be.

• KIISE Transactions on Computing Practices
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• v.20 no.9
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• pp.492-497
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• 2014

In this paper, we propose a method of retrieving opinioned tweets in Twitter, which is the one of the popular Social Network Services and shares diverse opinions among various users. In typical opinion retrieval systems, they may consider the presence of sentiment phrases (subjectivity) as the important factor even if the subjective phrases are not related to a given query or speaker. To alleviate these problems, we utilized the syntactic structure of a sentence to identify the relationships between 1) subjectivity-query and 2) subjectivity-speaker and 3) the syntactic role of subjectivity. Besides, our learning-to-rank approach is trained to retrieve opinioned tweets based on query-relevance, textual features, user information, and Twitter-specific features. Experimental results on real world data show that our proposed method can achieve better performance than several baseline methods in terms of precision and nDCG.

• The Journal of Information Systems
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• v.32 no.3
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• pp.151-164
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• 2023

Purpose This study aims to analyze the current status of consumer awareness on Internet banks by conducting a full investigation and collecting user opinions presented on Google Play. After cateogorizing the current dissatisfaction, we would like to present not only the direction of the Internet bank service of but also the improvements of the platform. Design/methodology/approach Using opinion mining, subjectivity analysis, polarity analysis, and polarity information analysis of comments were conducted step by step to extract negative and positive keywords. The extracted keywords analyzed the weights of the frequently appearing positive and negative keywords using the TF-IDF model. Based on previous studies that negative information is more sensitive to positive information, we tried to confirm the connection, proximity, and mediation of negative keywords. Semantic Network Analysis (SNA) was used to visualize the connection relationship between the negative comment keywords of the three Internet banks. Findings Domestic Internet banks such as Kakao Bank, K-Bank, and Toss Bank have attracted a lot of attention even before they were established, and after establishment, they have secured a wide range of users through platforms that are completely different from existing banks. This study found out that the convenience of the app affects the opening and transaction of non-face-to-face accounts, which are characteristics of domestic Internet banks, which also affects the bank's business strategy. In addition, this study shows that the business characteristics of the company can be identified.

• Journal of the Korea society of information convergence
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• v.7 no.2
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• pp.49-57
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• 2014

Recently, opinion mining is introduced to extract useful information from SNS data and to evaluate the true intention of users. Opinion mining are required several efficient techniques to collect and analyze a large amount of SNS data and extract meaningful data from them. Therefore in this paper, we propose a parallel HDFS(Hadoop Distributed File System) and emotion functions based on Mapreduce to extract some emotional information of users from various unstructured big data on social networks. The experiment results have verified that the proposed system and functions perform faster than O(n) for data gathering time and loading time, and maintain stable load balancing for memory and CPU resources.

• Asian Journal for Public Opinion Research
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• v.12 no.2
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• pp.122-141
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• 2024

Drawing on mere exposure effect, we proposed that more exposure to a city, as measured by the number of channels of exposure, would increase familiarity, city image, and intention to visit that city. We conducted a survey of university students in seven Asian countries, asking them about a total of 14 cities, at least one from each of the surveyed countries. Exposure was found to be a significant antecedent and was most powerful when mediated by familiarity. Some types of exposure were stronger than others. Personal exposure, in the form of having visited a city or knowing someone who has, was the strongest type of exposure, with more than double the effect of media exposure. Social media, which is difficult to classify as either personal or media, was assessed separately and had a much smaller effect. The mere exposure effect exists whether the intention to visit a city is related to pleasure (tourism) or business.

• 한국정보통신설비학회:학술대회논문집
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• 2009.08a
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• pp.268-271
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• 2009

In this paper, we analyze social network status and suggest TV SNS Service. According to alexa.com's recent chart, there are three SNS sites (facebook, myspace, twitter) in global top 20 sites. SNS usage has increased dramatically. Recently many SNS are growing up by opening their platform that make it easy to develope new services and functions by third party developers. KT is implementing open platform that is support Widget and SNS service. And Recently Social TV comes into the spotlight. Social TV is combination of social media and TV contents. It is enable to exchange emotion and opinion by communication with other people when watching Video contents. We propose TV SNS Service that provides various services by using advantage of SNS system and Social TV.

• Journal of Digital Convergence
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• v.19 no.6
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• pp.225-232
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• 2021

Nowadays, opinion leaders influence the formation of public opinion on various issues in social network services. There has been a lack of research on the personal characteristics that inspire users to interact with opinion leaders and show intent to act. This paper verifies how the disposition of Facebook users' self-identity affects the quasi-social interaction with opinion leaders on Facebook and the intention to share information. As the perception and behavior of users on social media platforms differ depending on the type of issue, an online survey was conducted by classifying issue types into life culture and political sectors. Research found that personal identity had a significant positive effect on quasi-social interactions in the life culture and politics sectors, while group identity negatively affected quasi-social interactions. In addition, the intention to share information was confirmed to have a significant effect only in the life and culture areas of self-identity (social and group identity). Quasi-social interaction was confirmed to have a significant positive effect on all issue areas. The results of this study suggest the need to consider variations in opinion leader marketing strategies based on the types of self-identity of Facebook users in the future. In addition, the study shows that raising the level of quasi-social interaction at the corporate level without distinction of issue types can lead to effective results.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.05a
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• pp.750-752
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• 2010

MANET has some interest as a wireless mobile network supporting node mobility and having no additional infrastructure. Speed of mobile node on MANET is various from just slow speed of human's walk to vehicle's moving speed. In this study, VoIP performance of MANET is evaluated in the view of speed of mobile node. VoIP performance is studied on walking speed, vehicle speed and higher speed on MANET. PDR(Packet Delivery Ratio), MOS(Mean Opinion Score) are used as performance parameters.