• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.502-504
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• 2004

With rapidly growing of computer and internet technology, Internet-based tote-operation of robotic systems has created new opportunities in resource sharing, long-distance learning, and remote experimentation. In this paper, remote control system of a mobile robot through the internet has been designed. The internet users can access and command a mobile robot in the real time, receiving the robot's sensor data. The overall system has been tested and its usefulness shown through the experimental results.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.3
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• pp.1363-1376
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• 2020

An improved clustering scheme based on user group is proposed. Every two users are grouped among N-users in the allowed system according to their link gain from large to small. Each user group is numbered sequentially. Two user clusters are obtained according to the principle of maximizing link gain difference for the users in the first and last user groups. The remaining user groups are added to the two existing user clusters according to the parity of the group number. The clustering should be clustered again among the users in either user cluster if the throughput summation of a user cluster in NOMA is less than that of these users in orthogonal multiple access. The simulation results show that the proposed clustering scheme can increase the system throughput by about 8% compared with the hybrid clustering scheme when the number of users requiring service is 12.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.4 no.6
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• pp.1042-1062
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• 2010

Cooperative spectrum sensing (CSS) is an effective technology for alleviating the unreliability of local spectrum sensing due to fading/shadowing effects. Unlike most existing solutions, this paper considers the use of CSS technology in decentralized networks where a fusion center is not available. In such a decentralized network, some attackers may sneak into the ranks of cooperative users. On the basis of recent advances in bio-inspired consensus algorithms, an attack-proof, decentralized CSS scheme is proposed in which all secondary users can maintain cooperative sensing by exchanging information locally instead of requiring centralized control or data fusion. Users no longer need any prior knowledge of the network. To counter three potential categories of spectrum sensing data falsification (SSDF) attacks, some anti-attack strategies are applied to the iterative process of information exchange. This enables most authentic users to exclude potentially malicious users from their neighborhood. As represented by simulation results, the proposed scheme can generally ensure that most authentic users reach a consensus within the given number of iterations, and it also demonstrates much better robustness against different SSDF attacks than several existing schemes.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.3
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• pp.1311-1324
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• 2019

In the traditional cellular network communication, the cellular user and the base station exchange information through the uplink channel and downlink channel. Meanwhile, device-to-device (D2D) users access the cellular network by reusing the channel resources of the cellular users. However, when cellular user channel conditions are poor, not only D2D user cannot reuse its channel resources to access the network, but also cellular user's communication needs cannot be met. To solve this problem, we introduced a novelty D2D communication mechanism in the downlink, which D2D transmitter users as half-duplex (HD) relays to assist the downlink transmission of cellular users with reusing corresponding spectrum. The optimization goal of the system is to make the cellular users in the bad channel state meet the minimum transmission rate requirement and at the same time maximize the throughput of the D2D users. In addition, i for the purpose of improving the efficiency of relay transmission, we use two-antenna architecture of D2D relay to enable receive and transmit signals at the same time. Then we optimized power of base station and D2D relay separately with consideration of backhaul interference caused by two-antenna architectures. The simulation results show that the proposed HD relay strategyis superior to existing HD and full-duplex (FD) models in the aspects of system throughput and power efficiency.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.12
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• pp.6034-6056
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• 2018

This paper describes two user studies in remote collaboration between two users with a video conferencing system where a remote user can draw annotations on the live video of the local user's workspace. In these two studies, the local user had the control of the view when sharing the first-person view, but our interfaces provided instant control of the shared view to the remote users. The first study investigates methods for assisting drawing annotations. The auto-freeze method, a novel solution for drawing annotations, is compared to a prior solution (manual freeze method) and a baseline (non-freeze) condition. Results show that both local and remote users preferred the auto-freeze method, which is easy to use and allows users to quickly draw annotations. The manual-freeze method supported precise drawing, but was less preferred because of the need for manual input. The second study explores visual notification for better local user awareness. We propose two designs: the red-box and both-freeze notifications, and compare these to the baseline, no notification condition. Users preferred the less obtrusive red-box notification that improved awareness of when annotations were made by remote users, and had a significantly lower level of interruption compared to the both-freeze condition.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.18 no.7
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• pp.1868-1887
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• 2024

Recommendation systems research is a subfield of information retrieval, as these systems recommend appropriate items to users during their visits. Appropriate recommendation results will help users save time searching while increasing productivity at work, travel, or shopping. The problem becomes more difficult when the items are geographical locations on the ground, as they are associated with a wealth of contextual information, such as geographical location, opening time, and sequence of related locations. Furthermore, on social networking platforms that allow users to check in or express interest when visiting a specific location, their friends receive this signal by spreading the word on that online social network. Consideration should be given to relationship data extracted from online social networking platforms, as well as their impact on the geolocation recommendation process. In this study, we compare the similarity of geographic locations based on their distance on the ground and their correlation with users who have checked in at those locations. When calculating feature embeddings for users and locations, social relationships are also considered as attention signals. The similarity value between location and correlation between users will be exploited in the overall architecture of the recommendation model, which will employ graph convolution networks to generate recommendations with high precision and recall. The proposed model is implemented and executed on popular datasets, then compared to baseline models to assess its overall effectiveness.

• Korean journal of communication and information
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• v.30
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• pp.143-174
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• 2005

This study aims at applying Chaffee & McLeod's co-orientation model to Internet portal news providers and users to find out their mutual understanding toward various features of online news. Included in those features are interactivity, expansion of user role, larger choices(user characteristics), real time update of news, limitless quantity, contextualized contents through hypertext, data base service, and multimedia contents(contents characteristics). To test the level of agreement, accuracy and congruency between the parties, a survey was conducted among 105 portal news providers from 11 online news media, and 105 portal news users between ages 20 and 40. The result indicated that both portal news providers and users showed agreement for user characteristics, but by and large displayed either ignorance or partial congruency toward contents characteristics. Communication between portal news providers and users are thus exported to increase until it reaches the point where the internet's newly born identity as a news medium gets finally stabilized.

• Journal of Internet Computing and Services
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• v.12 no.5
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• pp.29-37
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• 2011

Recently, many user-participating web services have been used widely as the evolution of internet web technology has rapidly been developed. Users share various content and opinion on line using a site like ‘Social bookmarking.’ Users can share others’ bookmarking history and create tags while bookmarking web sites; we call it collaborative tagging. In this paper, we studied empirical analysis for widely used social bookmarking and collaborative tagging which the result shows minority of users is actively using the bookmarking and a few sites and tags are used by majority of the users. 24% users tagged 80%, 75% sites and 81% tags were tagged below than 3 times. Types of bookmarking activities were found different by users and early appointed tags get more frequency by majority. We also identified relative proportions of tags on certain sites are becoming convergence gradually. We expect the result of this paper will give opportunities to help further developing social bookmarking system.

• Journal of the Korean Society of Clothing and Textiles
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• v.26 no.5
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• pp.642-653
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• 2002

The purposes of this studs were 1) to identify web navigation values and classify consumers based on these values and 2) to determine differences between consumer groups and between types of shopping mall in evaluation of website attributes when shopping apparel. The data were collected via a self-administered questionnaire from 204 male and female students who experienced shopping at the website, living in Cheju and analyzed by factor analysis, cluster analysis and t-test. Two factors of navigation value were found and labeled as; information value and entertainment value. Two groups were identified based on navigation value; users of information value (53%) and users of entertainment value (47%). Significant differences between two groups were found in evaluating website attributes selling products of various types regarding apparel products and processes for information search, order and payment. However, for shopping mall website selling only apparel products, differences between two groups were not significant in evaluating most attributes except for two items to evaluate apparel products. Differences between shopping mall types (shopping malls selling products of various types and selling only apparel product) were significant in evaluation of internet users of information value regarding attributes of apparel products while differences between shopping mall types were not significant in evaluation of users of entertainment value regarding all attributes. Internet users of information value showed favor to shopping mall website of department store type chi e internet users of entertainment value showed favor to shopping mall website selling only apparel products.

• Journal of the Korea Society of Computer and Information
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• v.10 no.6 s.38
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• pp.269-278
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• 2005

To justify the economic impacts of the internet access management is a purpose of this paper. Previous researches on economic justification were reviewed and the internet access management system. sniffer, and firewall were implemented to monitor real-time sessions and to record blocked attempts. This paper suggests the impact factors and measurement methods to justify the economic values of the internet access management system. Finally, this paper Proves that the overall impacts of the internet access management system have a Positive value because filtering mechanisms cause users to lose a small number of URLs including useful information and to diminish refreshment but save users from various risk points and enhance labor productivity.