• Journal of KIISE:Information Networking
• /
• v.28 no.4
• /
• pp.570-577
• /
• 2001

In recent years, Internet-based application services on the mobile environment have been activated, and the developments of mobile internet application for user authentication and privacy have been required. Especially, the research for preventing disclosure of identity caused by user mobility is on the progress. In this paper, we introduce the study of an authentication protocol for anonymity and untraceability supporting the protection of user identity and the authenticated secure association mechanism between mobile hosts and remote domains. In this protocol use public cryptography.

• International journal of advanced smart convergence
• /
• v.9 no.3
• /
• pp.42-48
• /
• 2020

These days people are overwhelmed by information on the Internet thus searching for useful information becomes burdensome, often failing to acquire some in a reasonable time. Recommender systems are indispensable to fulfill such user needs through many practical commercial sites. This study proposes a novel similarity measure for user-based collaborative filtering which is a most popular technique for recommender systems. Compared to existing similarity measures, the main advantages of the suggested measure are that it takes all the ratings given by users into account for computing similarity, thus relieving the inherent data sparsity problem and that it reflects the uncertainty or vagueness of user ratings through fuzzy logic. Performance of the proposed measure is examined by conducting extensive experiments. It is found that it demonstrates superiority over previous relevant measures in terms of major quality metrics.

• International journal of advanced smart convergence
• /
• v.9 no.3
• /
• pp.49-58
• /
• 2020

Non-orthogonal multiple access (NOMA) has been recognized as a significant technology in the fifth generation (5G) and beyond mobile communication, which encompasses the advanced smart convergence of the artificial intelligence (AI) and the internet of things (IoT). In NOMA, since the channel resources are shared by many users, it is essential to establish the user fairness. Such fairness is achieved by the power allocation among the users, and in turn, the less power is allocated to the stronger channel users. Especially, the first and second strong channel users have to share the extremely small amount of power. In this paper, we consider the power optimization for the two users with the small power. First, the closed-form expression for the power allocation is derived and then the results are validated by the numerical results. Furthermore, with the derived analytical expression, for the various channel environments, the optimal power allocation is investigated and the impact of the channel gain difference on the power allocation is analyzed.

• International Journal of Internet, Broadcasting and Communication
• /
• v.8 no.2
• /
• pp.38-42
• /
• 2016

In this paper, we propose 3-factor mobile banking authentication scheme applied to face recognition techniques with existing certificate and OTP. An image of the user's face is captured by smart phone camera and its brightness processing of the contour of a face and background by n of X and Y points. Then, distance between the point of eyes, nose and mouth from captured user's face are compared with stored facial features. When the compared results corresponding to the data that stored in a face recognition DB, the user is authenticated.

• International Journal of Internet, Broadcasting and Communication
• /
• v.8 no.3
• /
• pp.25-30
• /
• 2016

User-generated content (UGC) satirizing the presidential candidates was widespread during the 2016 election in Taiwan. Using an experimental design, this study explored the predictors of viewer agreement to satirical UGC, and its influence on viewer attitudes towards candidates after watching the satirical videos from YouTube. Results showed that participants' agreement with the satirical UGC was predicted by their political cynicism and political information efficacy, but not by candidate favorability. Watching the UGC satirizing the presidential candidates effected the favorability toward the male candidates but not the female candidate. In addition, the evidence suggested that the frequency of exposure to satirical UGC is related to political information efficacy, but not with political cynicism or candidate favorability.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.9 no.1
• /
• pp.20-33
• /
• 2015

Spectrum sensing is a key component of cognitive radio. The prediction of the primary user status in a low signal-to-noise ratio is an important factor in spectrum sensing. However, because of noise uncertainty, secondary users have difficulty distinguishing between the primary signal and an unauthorized signal when an unauthorized user exists in a cognitive radio network. To resolve the sensitivity to the noise uncertainty problem, we propose an entropy-based spectrum sensing scheme to detect the primary signal accurately in the presence of an unauthorized signal. The proposed spectrum sensing uses the conditional entropy between the primary signal and the unauthorized signal. The ability to detect the primary signal is thus robust against noise uncertainty, which leads to superior sensing performance in a low signal-to-noise ratio. Simulation results show that the proposed spectrum sensing scheme outperforms the conventional entropy-based spectrum sensing schemes in terms of the primary user detection probability.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.10 no.3
• /
• pp.1289-1310
• /
• 2016

Dynamic ID-based authentication solves the ID-theft problem by changing the ID in each session instead of using a fixed ID while performing authenticated key exchanges between communicating parties. User anonymity is expected to be maintained and the exchanged key kept secret even if one of the long-term keys is compromised in the future. However, in the conventional dynamic ID-based authentication scheme, if the server's long-term key is compromised, user anonymity can be broken or the identities of the users can be traced. In addition, these schemes are vulnerable to replay attacks, in which any adversary who captures the authentication message can retransmit it, and eventually cause the legitimate user to be denied service. This paper proposes a novel dynamic ID-based authentication scheme that preserves forward anonymity as well as forward secrecy and obviates replay attacks.

• Proceedings of the KIEE Conference
• /
• 2007.04a
• /
• pp.325-327
• /
• 2007

In this paper, we implement the internet- based remote control system for intelligent robot. For remote control of the robot, it uses the socket communication of the TCP/IP. It consists of- the user interface and the robot control interface. Robot control interface transmits the navigation and environmental informations of the robot into the user interface. In order to transmit the large environmental images, a JPEG compression algorithm is used. User interface displays the navigation status of the robot and transmits the navigation order into the robot control interface. Also, we propose the design method of the fuzzy controller using navigation data acquired by expert's knowledge or experience. To do this, we use virus-evolutionary genetic algorithm(VEGA). Finally, we have shown the proposed system can be operated through the real world experimentations.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.7 no.12
• /
• pp.3135-3148
• /
• 2013

The popularization of streaming networks and mobile devices brings a new kind of network called mobile peer-assisted streaming network. In this network, service provider not only offers downloading services, but also pre-pushes resources to users for caching. Users can download their demanded resources while working as servers for uploading the cached data. Also the mobile characteristic makes high package losing probability in this network. So we study how the service provider pre-pushes or the user downloads resources efficiently and effectively while considering the package losing in this paper. We build utility models for service provider and user, and solve the models using Bellman's theory to achieve Nash Equilibrium which shows the service provider's optimal pre-pushing speed and user's optimal downloading speed. The numerical simulation demonstrates the efficiency and effectiveness of our proposed pre-pushing and downloading scheme by comparing to the traditional scheme.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.6 no.9
• /
• pp.2086-2097
• /
• 2012

A terminal-based dynamic clustering algorithm is proposed in a multi-cell scenario, where the user could select the cooperative BSs from the predetermined static base stations (BSs) set based on dynamic channel condition. First, the user transmission rate is derived based on linear precoding and per-cell feedback scheme. Then, the dynamic clustering algorithm can be implemented based on two criteria: (a) the transmission rate should meet the user requirement for quality of service (QoS); (b) the rate increment exceeds the predetermined constant threshold. By adopting random vector quantization (RVQ), the optimized number of cooperative BSs and the corresponding channel conditions are presented respectively. Numerical results are given and show that the performance of the proposed method can improve the system resources utilization effectively.