• Journal of Korea Multimedia Society
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• v.8 no.9
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• pp.1227-1238
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• 2005

Recently, with the advance of network and internet technologies, it is appeared the Problem that the digital contents such as image, voice and video are illegally pirated and distributed. To protect the copyright of the digital contents, the digital watermarking technology of inserting the provider's information into the contents has been widely used. In this paper, we propose the method of applying the digital watermarking into biometric information such as fingerprint and iris in order to prevent the problem caused by steal and misuse. For that, we propose the method of inserting watermark in frequency domain, compare the recognition performance before and aster watermark inserting. Also, we experiment the robustness of proposed method against blurring attack, which is conventionally taken on biometrics data. Experimental results show that our proposed method can be used for protecting iris and fingerprint data, efficiently.

• Journal of Advanced Marine Engineering and Technology
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• v.40 no.7
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• pp.622-628
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• 2016

The prosperity of IT technologies and the removal of restrictions regarding Unmanned Aerial Vehicles (UAVs), also known as drones, have driven growth in their popularity. However, without a proper solution to the problem of accident avoidance for UAVs, this popularity increases the potential for collisions between UAVs and between UAV and terrain features. These collisions can occur because UAVs to date have flown using radio control or image recognition based autonomous navigation. Therefore, we propose efficient UAV routing schemes to tackle the collision problem using vehicular communication systems. Performance evaluation by computer simulation shows that the proposed methods effectively reduce the collision probability and improve the routing efficiency of the UAV. Furthermore, the proposed algorithms are compatible and can be directly applied with small overhead to the commercial vehicular communication system implementation.

• The Transactions of the Korea Information Processing Society
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• v.6 no.6
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• pp.1667-1677
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• 1999

An effective allocation of requested number of processors to newly incoming tasks in two-dimensional (2D) mesh interconnection networks is very important for achieving the desired high performance and resource utilization. It also needs to guarantee the complete recognition of the free submeshes based on contiguous and available processors with minimum overhead. An efficient task allocation algorithm for 2D meshes is presented in this paper. By employing a new approach for searching the one-dimensional array, the proposed algorithm can find the available submesh without the scanning of the entire 2D array unlike earlier designs. As a result, the new algorithm can significantly reduce the task allocation time. Comprehensive computer simulation shows that the average allocation time and waiting delay are much smaller than earlier irrespective of the size of meshes. The hardware overhead is comparable to other algorithms.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.12
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• pp.780-788
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• 2019

This study is intended to analyze flipped classroom learning activities, which have recently been spotlighted as a learner-centered teaching method in universities, from the perspective of cultural and historical activity theory. A survey and some participation observations were conducted with one professor and the students who participated in Educational Methods and Technology courses at A university. The components of the flipped classroom learning activities were analyzed based on the model of the activity system, and contradictions that appeared in the interactions between components were analyzed. Four implications were proposed for a more advanced flipped classroom learning activity system: the professor's and the learners' true identity recognition and role performance, strengthening the organic link between online and offline activities, support for alleviating the burden of teaching and learning preparation, and readjusting the system to support its smooth operation.

• Journal of Korean society of Dental Hygiene
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• v.9 no.3
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• pp.479-492
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• 2009

This study was conducted to find out the relationship between dental anxiety and self-efficacy, physical and psychological condition and expected self-efficacy. The objective of this study was also to provide foundation for appropriate dental hygiene intervention model for scaling. In this study, anxiety reactions were measured among 178 patients, who made appointment with dental hygienists for scaling between May and July, 2009. The analysis was done in SPSS 12.0 statistical program which confirmed Cranach's alpha value. Technical statistics, t-test and One-way ANOVA, correlation and regression were also used. The result of the study is following: While dental hygienist conducts scaling, the dental anxiety was each measured in following categories: Thus male, age between 40 and 50, single, high school graduated and unemployed were measured highest dental anxiety among various groups. Dental Fear Scale demonstrated the validity of relationship between dental anxiety and self efficacy. The correlation was equated as r=-.409(p<0.01). In the other words, the higher self efficacy, the lower dental anxiety. The relationship between dental anxiety and physical and physiological condition was relevant. Physical condition was r=-.229(p<0.01) And then, the psychological condition was r=-.299(p<0.01). Thus, better physical and physiological condition results in less dental anxiety. The relationship between expected Self-efficacy and dental anxiety is also valid. The dental anxiety after performance accomplishment is r=-.239(p<0.01), after vicarious experience is r=-.195(p<0.01), after verbal persuasion is r=-.152(p<0.05), after recognition of physiological state is r=-.410(p<0.01). In conclusion, sex, age, marital status, education level, employment, physical condition, physiological condition are all relevant to dental anxiety(F=8.834). Both independent and dependent variables p<.05 have 37.5% persuasiveness.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.37 no.6
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• pp.545-550
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• 2013

We present a tactile information transceiver using a friction-tunable slider-pad. While previous tactile information devices were focused on either input or output functions, the present device offers lateral position/vertical direction detection and texture expression. In characterizing the tactile input performance, we measured the capacitance change due to the displacement of the slider-pad. The measured difference for a z-axis click was 0.146 nF/$40{\mu}m$ when the x-y axis navigation showed 0.09 nF/$750{\mu}m$ difference. In characterizing the texture expression, we measured the lateral force due to a normal load. We applied a voltage between parallel electrodes to induce electrostatic attraction in DC and AC voltages. We measured the friction under identical fingertip action conditions, and obtained friction in the range of 32-152 mN and lateral vibration in the force range of 128.1 mN at 60 V, 2 Hz. The proposed device can be applied to integrated tactile interface devices for mobile appliances.

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.6
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• pp.1497-1508
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• 1993

Real-time mobile robot controllers usually have been designed focused on control theory without paying attention to the importance of system integration. This paper demonstrates that autonomous mobile robots require a real-time controller with a wide range of capabilities in addition to control theory. An architectural frame work supporting these capabilities has been designed in actual hardware environments. Individual modules such as a path planner, a path tracking controller, position estimators, wheel controllers and other cruical elements have been successfully integrated into the control system using this frame work. The overall performance of the system was investigated via a series of tracking experiments with a prototype mobile robot named LCAR deveoped in the laboratory. The context of the research involves the architecture, its implementation and experimental results.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.12B
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• pp.1481-1488
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• 2011

Recently, Hacking Attacks are appearing as a various Attack techniques with evolution of the Network. and most of the network through a Various Security Systems are responding to an attack. In addition, it should be placed adding the Security Systems to protect the Internal Network's Information assets from External attacks. But, The use of Security Systems inside the network makes a significant impact on Security and Performance, as well as a result causes Economic Additional Costs. Therefore, In this paper, it will be to analyze by associated a case study and experimental results about the Additional Costs Factors(Variable situations difficult to predict and Information Security Recognition levels, Security Systems, Information Asset Assessment). This is expected to serve as a valuable Information for the Reduction of an Costs in a Network deployment and Design in a future.

• The Journal of the Convergence on Culture Technology
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• v.6 no.2
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• pp.449-454
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• 2020

This paper proposes a machine learning-based emotion analysis system that detects a user's depression through their SNS posts. We first made a list of keywords related to depression in Korean, then used these to create a training data by crawling Twitter data - 1,297 positive and 1,032 negative tweets in total. Lastly, to identify the best machine learning model for text-based depression detection purposes, we compared RNN, LSTM, and GRU in terms of performance. Our experiment results verified that the GRU model had the accuracy of 92.2%, which is 2~4% higher than other models. We expect that the finding of this paper can be used to prevent depression by analyzing the users' SNS posts.

• Journal of the Korea Convergence Society
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• v.9 no.2
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• pp.7-12
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• 2018

With our society entering the Fourth Industrial Revolution, there has been heightened interest in coding education, which has led to an increased number of coding classes offered in schools. Once catered to degree holders only, coding courses are now being offered as liberal arts courses to even non-majors. As the importance of computing abilities and creativity-oriented education through software learning becomes increasingly pronounced, the need for research on effective coding learning is growing more urgent. The present study sought an effective coding education model that would encourage and enhance learners' participation and interest in coding. The proposed learning model is designed to invoke learner's recognition of various coding grammars and data search in the process of designing and performing their own unique project. Application of the proposed learning model and analysis of such case studies showed improvement in learning outcomes. One can expect improved performance among learners if the proposed learning model is applied to various coding courses.