• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.298-298
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• 2009

Touch screen using in portable devices is expanding continuously, has become particularly strong in mobile phones. These trends are able to open the "New Horizon" which refers the design and usability of mobile phones and provide "New Experience" which users have never been experienced on mobile phones. This research argues new usability issues and important points which can be occurred in touch based mobile phones as user experience point of view.

• Proceedings of the IEEK Conference
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• 2002.06a
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• pp.105-108
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• 2002

This paper analytical models of a centralized approach based on SNMP Protocol, distributed approach based on mobile agent, and mixed model which is tile existing mobile agent model in order to overcome large communication numbers of SNMP and accumulated data of mobile agent. And then, we compare and analyze these analytical models. Performance evaluation results show that performance of mobile agent and the mixed model is less sensitive to the network traffic and more profitable for complex network environment than that of SNMP.

• Journal of Institute of Control, Robotics and Systems
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• v.13 no.7
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• pp.664-670
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• 2007

This study deals with image-based visual servoing for automatic recharging of mobile robot. Because mobile robot must be recharged periodically, it is necessary to detect and move to docking station. Generally, laser scanner is used for detect of position of docking station. CCD Camera is also used for this purpose. In case of using cameras, the position-based visual servoing method is widely used. But position-based visual servoing method requires the accurate calibration and it is hard and complex work. Another method using cameras is image-based visual servoing. Recently, image based visual servoing is widely used for robotic application. But it has a problem that cannot have linear trajectory in the 3-dimensional space. Because of this weak point, image-based visual servoing has a limit for real application. In case of 2-dimensional movement on the plane, it has also similar problem. In order to solve this problem, we point out the main reason of the problem of the resolved rate control method that has been generally used in the image-based visual servoing and we propose an image-based visual servoing method that can reduce the curved trajectory of mobile robot in the cartesian space.

• IEMEK Journal of Embedded Systems and Applications
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• v.10 no.4
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• pp.241-255
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• 2015

Recent network environment has been rapidly evolved to cloud computing environment based on the development of the Internet technologies. Furthermore there is an increasing demand on mobile cloud computing due to explosive growth of smart devices and wide deployment of LTE-based cellular networks. Thus mobile Desktop-as-a-Service(DaaS) could be a pervasive service for nomadic users. In addition, video streaming traffic is currently more than two-thirds of mobile traffic and ever increasing. All such trends enable that video streaming in mobile DaaS could be an important concern for mobile cloud computing. It should be noted that the performance of the Transmission Control Protocol(TCP) on cloud host servers greatly affects Quality of Service(QoS) of video streams for mobile users. With widely deployed Linux server platforms for cloud computing, in this paper, we conduct an experimental analysis of the twelve Linux TCP variants in mobile DaaS environments. The results of our experiments show that the TCP Illinois outperforms the other TCP variants in terms of wide range of packet loss rate and propagation delay over LTE-based wireless links between cloud servers and mobile devices, even though TCP CUBIC is usually used in default in the current Linux systems.

• Korean Journal of Community Nutrition
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• v.22 no.6
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• pp.485-494
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• 2017

Objectives: The objective of this study was to develop mobile phone application for image-based dietary assessment and evaluate satisfaction regarding respondent's use of the mobile phone application. Methods: We developed a mobile phone application to assess dietary intakes using 24 hour dietary recall. After initial development, application was reviewed by ten adults and revised based on their comments. We recruited 192 volunteers (92 males, 100 females) to use the mobile phone application and to respond to a satisfaction survey. Participants were instructed to use the mobile phone application with fiducial marker five centimeter in width, length and two centimeter height at each eating occasion during designated 4 days, capturing $45^{\circ}$ angle and $90^{\circ}$ angle images of all food and beverage items before and after consumption. After using the mobile phone application for 4 days, participants were asked to complete an online questionnaire on the satisfaction of the mobile phone app. User satisfaction items composed of 12 questions of application user interface, 8 questions of emotional response, 9 questions of eating behavior in 5 likert scale. Participants were also asked to provide additional open-ended comments on the use of mobile phone application. Statistical analysis was performed by using the SPSS 23.0 (Statistical Package for the Social Science). Results: The average user interface score was $2.82{\pm}1.08$, which was close to the 'normal' response. Responses for emotion and eating behavior also were borderline to the 'normal'. Conclusions: This study found that the mobile phone application using 24-hour recall was acceptable to be used to assess dietary intakes for several days. However, there should be a need for such technology to be user-oriented instead of researcher-oriented. Easy and cost-effective new technology is needed for estimating the amounts of food eaten automatically when the photos are taken.

• International Journal of Computer Science & Network Security
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• v.21 no.12spc
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• pp.375-382
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• 2021

The paper introduces a model for evaluating and prioritizing mobile quality attributes and refactoring techniques through the examination of their effectiveness during the mobile application development process. The astonishing evolution of software and hardware has increased the demand for techniques and best practices to overcome the many challenges related to mobile devices, such as those concerning device storage, network bandwidth, and energy consumption. A number of studies have investigated the influence of refactoring, leading to the enhancement of mobile applications and the overcoming of code issues as well as hardware issues. Furthermore, rapid and continuous mobile developments make it necessary for teams to apply effective techniques to produce reliable mobile applications and reduce time to market. Thus, we investigated the influence of various refactoring techniques on mobile applications to understand their effectiveness in terms of quality attributes. First, we extracted the most important mobile refactoring techniques and a set of quality attributes from the literature. Then, mobile application developers from nine mobile application teams were recruited to evaluate and prioritize these quality attributes and refactoring techniques for their projects. A prioritization-based model is examined that integrates the lightweight multi-criteria decision making method, called the best-worst method, with the process of refactoring within mobile applications. The results prove the applicability and suitability of adopting the model for the mobile development process in order to expedite application production while using well-defined procedures to select the best refactoring techniques. Finally, a variety of quality attributes are shown to be influenced by the adoption of various refactoring techniques.

• Journal of the Ergonomics Society of Korea
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• v.29 no.4
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• pp.527-532
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• 2010

Product developers nowadays must consider not only the technological satisfaction of consumers but their affective needs as well. These affective needs are greatly affected by the appearance and performance functions of the product, which are simply called in this study appearance-based affection and performance-based affection. This study examined these two affective factors that must be considered while designing mobile phones. Extracted relationship between the two factors was processed in five steps. The first step includes gathering potential affective expressions that are needed to evaluate the levels of consumer's affection for mobile phone design in the pool of adjectives. In the second step, a simple frequency analysis was done from a consumer survey to extract frequently used affective expression. The third step was to extract primary tasks for mobile phones and to perform an experiment or a survey for the evaluation of mobile phones using those tasks. Representative affective factors were then extracted in the fourth step based on factor analysis. Finally, using ANOVA, the extracted representative affective factors were prioritized to draw a relationship between appearance-based affection and performance-based affection. The result of this study suggests each of appearance-based affections and performance-based affections that should be considered in designing mobile phones.

• Proceedings of the KAIS Fall Conference
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• 2003.11a
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• pp.113-117
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• 2003

As the wireless communication technology advances rapidly, a personalization technology can be incorporated with the mobile Internet environment, which is based on location-based services to support more accurate personalized services. A location-based personalized recommender system is one of the essential technologies of the location-based application services, and is also a crucial technology for the ubiquitous environment. In this paper we propose a framework of a location-based personalized recommender system for the mobile Internet environment. The proposed system consists of three modules the interface module, the neighbor selection module and the prediction and recommendation module. The proposed system incorporates the concept of the recommendation system in the Electronic Commerce along with that of the mobile devices for possible expansion of services on the mobile devices. Finally a service scenario for entertainment recommendation based on the proposed recommender system is described.

• Journal of the Korean Society of Industry Convergence
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• v.18 no.2
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• pp.90-98
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• 2015

This research propose with image-based visual a new approach to design a feedback control of mobile robot. because mobile robot must be recharged periodically, it is necessary to detect and move to docking station. Generally, laser scanner is used for detect of position of docking station. CCD Camera is also used for this purpose. In case of using camera, the position-based visual servoing method is widely used. But position-based visual servoing method requires the accurate calibration and it is hard and complex work. Another method using cameras is inmage-based visual feedback. Recently, image based visual feedback is widely used for robotic application. But it has a problem that cannot have linear trajectory in the 3-dimensional space. Because of this weak point, image-based visual servoing has a limit for real application. in case of 2-dimensional movement on the plane, it has also similar problem. In order to solve this problem, we point out the main reason of the problem of the resolved rate control method that has been generally used in the image-based visual servoing and we propose an image-based visual feedback method that can reduce the curved trajectory of mobile robot in th cartesian space.

• International Journal of Advanced Culture Technology
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• v.2 no.1
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• pp.1-13
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• 2014

In next-generation wireless networks, provisioning of IP-based network architecture and seamless transmission services are very important issues for mobile nodes. For this reason, a mobility management mechanism to support global roaming is highly regarded. These technologies bring a broader life by using a global roaming account through the connection of multiple devices or technology to mobile users; they also provide real-time multimedia services. This paper presents a comprehensive performance analysis of fast handover for hierarchical mobile IPv6 (F-HMIPv6), hierarchical mobile IPv6 (HMIPv6), Proxy Mobile IPv6 (PMIPv6), and fast Proxy Mobile IPv6 (FPMIPv6) using the fluid-flow model and random-walk model. As a result, the location update cost of the PMIPv6 and FPMIPv6 is better than that of HMIPv6 and F-HMIPv6. These results suggest that the network-based mobility management technology is superior to the hierarchical mobility management technology in the mobility environment.