• Journal of KIISE:Information Networking
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• v.35 no.2
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• pp.130-138
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• 2008

The scheme for recognizing the channel availability is one of the most important research issues in cognitive radio systems utilizing unused frequency bands. In this paper, we propose a novel scheme of selecting sensing channel in order to improve the sensing ability of frequency status in cognitive radio ad hoc networks. To fully exploit the sensing ability of each cognitive radio user, we adopt a master for a cluster which is made of several cognitive radio users. By gathering and analyzing the sensing information from cognitive radio users in the cluster, the cooperative sensing is realized. Since the transmission range of a licensed user is limited, it is possible that a master determines different sensing channels to each cognitive radio users based on their location. By making cognitive radio users sense different channels, the proposed scheme can recognize the state of wireless spectrum fast and precisely. Using the simulation, we compare the performance of the proposed scheme with those of two different compared schemes that one makes cognitive radio users recognize the frequency status based on their own sensing results and the other shares frequency status information but does not utilize the location information of licensed user. Simulation results show that the proposed scheme provides available channels as many as possible while detecting the activation of licensed user immediately.

• Journal of the Korean Association of Geographic Information Studies
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• v.1 no.1
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• pp.70-85
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• 1998

This study intends to identify the effects of user attitude, user education & training on the information systems implementation performance. In order to obtain data, survey questionnaires were distributed to the users of 'D' company, the major findings can be summarized as follows. First, it's suggested from the analyses that user attitude and user education & training independently have statistically significant effects on information systems implementation performance. Second, it's revealed that even though the interaction effects by both user attitude and user education & training have positive effects on the level of usage, but have no statistically significant effects on satisfaction level. Based on these results, it's recommended to convert user attitude favorably toward user environment and to increase the level of user education & training, in order to promote information systems implementation performance. Especially, differentiated user education & training are highly recommended.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.147.1-147
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• 2001

Future robots, especially service and personal robots, will need much more intelligence, robustness and user-friendliness. The ability to learn contributes to these characteristics and is, therefore, becoming more and more important. Three of the numerous varieties of learning are discussed together with results of real-world experiments with three autonomous robots: (1) the acquisition of map knowledge by a mobile robot, allowing it to navigate in a network of corridors, (2) the acquisition of motion control knowledge by a calibration-free manipulator, allowing it to gain task-related experience and improve its manipulation skills while it is working, and (3) the ability to learn how to perform service tasks ...

• The Korean Journal of Community Living Science
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• v.15 no.3
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• pp.3-14
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• 2004

This study examined how product characteristics and system characteristics have affected user's economic, psychological and operating satisfaction and intention of repurchase in Internet shopping malls. The results of the study were as follows: First, it showed that product characteristics and user satisfaction have significant differences; the ability to recognize economic and psychological user satisfaction differs according to the characteristics of the product. It also showed that the degree of psychological and operating user satisfaction varies according to the convenience of order and payment as well as the convenience of the system and customer service. Second, it was found that economic, psychological and operational user satisfaction had an effect on customer's intention to repurchase. This study, focusing on particular variants of on-line shopping, found that characteristics of product and system had a great impact on user satisfaction and intention to repurchase. For the firms who run internet shopping malls, therefore more attention should be directed to the convenience of products and system problems in their services since it is so easy for customers to move to another shopping site with a simple click. The result of such an investigation may lead customers to repurchase by increasing their satisfaction with the shopping services.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.9
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• pp.3444-3457
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• 2021

In the field of anti-jamming based on dynamic spectrum, most methods try to improve the ability to avoid jamming and seldom consider whether the jammer would perceive the user's signal. Although these existing methods work in some anti-jamming scenarios, their long-term performance may be depressed when intelligent jammers can learn user's waveform or decision information from user's historical activities. Hence, we proposed a hidden anti-jamming method to address this problem by reducing the jammer's sense probability. In the proposed method, the action correlation between the user and the jammer is used to evaluate the hiding effect of the user's actions. And a deep reinforcement learning framework, including specific action correlation calculation and iteration learning algorithm, is designed to maximize the hiding and communication performance of the user synchronously. The simulation result shows that the algorithm proposed reduces the jammer's sense probability significantly and improves the user's anti-jamming performance slightly compared to the existing algorithms based on jamming avoidance.

• Proceedings of the Korean Information Science Society Conference
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• 2011.06a
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• pp.116-119
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• 2011

Mobile devices are increasingly used, and changed persons' social habits of creating new relationship. While existed systems can not satisfied the principles of user-centered, convenient and ensure privacy. This paper describes an intelligent name-card exchange technique in context-aware smart phone, which has no verbose user operation, ability of intelligent match based on context-aware information, and privacy protection.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.4 no.3
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• pp.271-276
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• 2004

This paper is a research on the dynamic signature verification of error rate which are false rejection rate and false acceptance rate, the size of signature verification engine, the size of the characteristic vectors of a signature, the ability to distinguish similar signatures, the processing speed and so on. Also, we present our efficient user interface and performance results.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.1201-1206
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• 2007

Robot simulation technique is essential not only for robot developers to design robotic systems but also for robot operators to predict robot motion, configure system layout, and increase robot ability. However, commercial robot simulation software such as ROBCAD, IGRIP, and so on are expensive and sometimes they are difficult to customize into industrial purpose programming for users. Therefore, user-based simulation programming is required to magnify the efficiency of robot system. In this paper, we show the methodology of developing user-based robot simulation programming using PC(personal computer), Open-Inventor, and Windows Programming. The developed programming has been successfully applied to welding robot systems of a shipbuilding industry. Also, the methodology presented here can be easily extended to simulate manipulators of other typed mechanism on user's PC.

• Journal of Advanced Navigation Technology
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• v.15 no.4
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• pp.626-631
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• 2011

In this paper, the methods of designing and implementing user interaction using jQuery in Web Application are suggested. While computing ability of smart devices grows up, web application technology is generalized. So JavaScript is one of noticeable web application technologies, and jQuery is the most popular JavaScript framework. We described basic grammar, scalability and plug-ins of jQuery. We categorized user interactions and animations and described methods to implement it.

• Korean Institute of Interior Design Journal
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• v.15 no.2 s.55
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• pp.99-107
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• 2006

People with visual impairments are difficult to go to education facility by themselves, because of their limited visual ability, orientation, and usability field, so they prefer dormitories. Those dormitories playa role in living space, education, communication and culture function. Therefore those facilities planned more user centered design, since they are influenced by user actability and their values. User centered designs that match between the user and space are understood as well as their characteristics and behavior. Especially for understanding their activity, observation is conducted about their behavior in dormitories. Thus the purpose of this study is suggested to be a basic source that planning about residential facility for people with visual impairments through interview and observation investigation by analysis that they resident in space motion and performance.