• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.11a
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• pp.330-331
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• 2006

Recently, plasma display panels (PDPs) are highlighted for the flat type display device. Therefore, much attention has been paid to secondary electron emission coefficient of the electrode protective material of PDPs. As PDPs is developing, the concern about secondary electron emission coefficient ($\gamma$) which is related with PDPs electrode protection material is increasing continually. So the concern about the way to how to measure secondary electron emission coefficient is on the rise. At present, the way to how to measure secondary electron emission coefficient is developed by some research groups, which is giving some research part's advance help. In this research, we have studied how to measure secondary electron emission coefficient which is related with various thin films more conveniently than previous measurement method. We studied the method of measurement of secondary electron emission coefficient (${\gamma}$) of amorphous silicon films by using Paschen's curve.

• Journal of the Korean Society of Safety
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• v.34 no.2
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• pp.56-62
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• 2019

Secondary accident is common type of accident which occurs in Korean highway tunnels. Fatality rate of secondary accidents in highway tunnels is six time higher than primary accidents. Video type VMS is a new way of providing information to road users which was recently introduced by Korean government to prevent secondary accidents in highway tunnels. In this study we compared changes in driver's behavior when information is provided by Text type and Video Type VMS. In addition to analyze effects of secondary accident reduction, driving behavior was analyzed based on providing advance information by video type VMS at tunnel entrance. Analysis showed that both text type and video type VMS has similar effect on driver behavior. Video type VMS showed positive effect on driver's behavior to prevent secondary accident when information is provided 1km ahead of accident. Considering there results and the short-term memory characteristics of driver, it was determined that information should be provide at about 650m from the entrance of the tunnel. The results of this study are consistent with the requirement that VMS should be installed at least 500m ahead of tunnel and produce more accurate providing information points. 650m is also appropriate interval for providing information in tunnel to cope with an accident ahead.

• East Asian mathematical journal
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• v.29 no.1
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• pp.101-107
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• 2013

We consider a cognitive network with a primary and a secondary channel. Primary users have higher priority on the usage of the primary channel, and secondary users are allowed to opportunistically access the primary channel at times when the channel is not occupied by primary users. The secondary channel is dedicated only to secondary users. An analytical model is presented to obtain the performance of an opportunistic spectrum access using both the primary and secondary channels, and is validated by simulations.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.11
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• pp.2547-2552
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• 2013

To achieve better performance in dynamic spectrum access networks, each secondary user tracks channels and chooses a good channel to transmit its packet. When all secondary users adopt the same dynamic spectrum access policy, they have similar channel information, which leads secondary users to choose the same channel and more collisions among them. To relieve this problem, we propose an access policy using belief vector tracking method for other competing secondary users. Simulation results are provided to show that the proposed policy yields better performance than the existing policies which do not take into account what other secondary users are doing.

• Proceedings of the Korean Information Science Society Conference
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• 2012.06d
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• pp.265-267
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• 2012

This paper analyzes network selection issues of secondary users (SUs) in Cooperative Cognitive Radio Networks (CRNs) by utilizing Queuing Model. Coordinating with Handover Cost-Based Network selection, this paper also addresses an opportunity for the secondary users (SUs) to enhance QoS as well as economics efficiency. In this paper, network selection of SUs is the optimal association between Overall System Time Minimization Problem evaluation of Secondary Connection (SC) and Handover Cost-Based Network selection. This will be illustrated by simulation results.

• Journal of information and communication convergence engineering
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• v.5 no.3
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• pp.223-228
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• 2007

This paper deals with the secondary excited induction generator applied to random wave input generation system. As it is preferred to stabilize the output voltage and frequency in the constant level, microcomputer controlled CSI connected to the secondary windings supplies the secondary current with slip frequency. For testing this method, the input torque simulator is constructed, according to the power flow analysis. The experimental and numerical results show the advantage of secondary excited induction generator system for the random input wave generation system.

• Proceedings of the Korean Society for Bioinformatics Conference
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• 2003.10a
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• pp.133-138
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• 2003

The prediction of protein secondary structure has been an important bioinformatics tool that is an essential component of the template-based protein tertiary structure prediction process. It has been known that the predicted secondary structure information improves both the fold recognition performance and the alignment accuracy. In this paper, we describe several novel ideas that may improve the prediction accuracy. The main idea is motivated by an observation that the protein's structural information, especially when it is combined with the evolutionary information, significantly improves the accuracy of the predicted tertiary structure. From the non-redundant set of protein structures, we derive the 'potential' parameters for the protein secondary structure prediction that contains the structural information of proteins, by following the procedure similar to the way to derive the directional information table of GOR method. Those potential parameters are combined with the frequency matrices obtained by running PSI-BLAST to construct the feature vectors that are used to train the support vector machines (SVM) to build the secondary structure classifiers. Moreover, the problem of huge model file size, which is one of the known shortcomings of SVM, is partially overcome by reducing the size of training data by filtering out the redundancy not only at the protein level but also at the feature vector level. A preliminary result measured by the average three-state prediction accuracy is encouraging.

• The Journal of Korean Association of Computer Education
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• v.10 no.4
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• pp.103-112
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• 2007

This study purposed to analyze problems in utilizing hardware and software invested for elementary and secondary school that were distributed through the education information project so far, and to make plans for substantial operation. In order to identify relevant problems and to draw up plans for substantial operation, this study analyzed relevant previous researches and investigated the current state of the utilization of educational information resources in school through question investigation. In addition, we visited elementary, secondary schools, and governmental departments of relevant personnel and had interviews with the people there. From this, we suggested the substance proposals of the educational information resources operation for elementary and secondary school. Therefore, the substance proposal to the information resource in education that was produced by this study would be useful to establish and execute relevant policy for elementary and secondary schools and governmental departments.

• Journal of Korea Multimedia Society
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• v.14 no.12
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• pp.1549-1558
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• 2011

In this paper, we address the problem of bandwidth sharing among multiple primary users and multiple secondary users in a cognitive radio network. In cognitive radio networks, effective spectrum assignment for primary and secondary users is a challenge due to the available broad range of radio frequency spectrum as well as the requisition of harmonious coexistence of both users. To handle this problem, firstly, Bertrand game model is used to analyze a spectrum pricing in which multiple primary users emulate with each other to acquire maximal profit. After that, we employ Cournot game to model the spectrum sharing of secondary users to obtain optimal profit for each user also. Simulation results show that our scheme obtains optimal solution at Nash equilibrium.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.20 no.6
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• pp.251-260
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• 2010

Through the convergence of medical services and the IT technique, the patient's personal health information computerization has been rapidly spread with propagation of electronic medical record(EHR). In addition, by entering u-health, the demand of the secondary use for public health, medical research, and medical service using electronic patient health care records are increasing. The personal health information secondary uses for the development of academic medical area and service, are very good thing. But, carelessly to use personal health information, the patient privacy would be damaged. However, there are not yet systematic studies about secondary use of personal health information. Therefore, in this paper, we analyze the difference of the internal and external bill for personal medical data secondary use and propose the direction of the medical service development and preservation of the individual's privacy.