• ETRI Journal
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• v.39 no.2
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• pp.264-274
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• 2017

Recently, mobile positioning enhancement has attracted much attention in the 3rd generation partnership project long-term evolution system. In particular, for urban canyon environments, the need for three-dimensional (3D) positioning has increased to enable the altitude of users to be measured. For several decades, several time difference of arrival (TDOA-) based 3D positioning methods have been studied; however, they are only available when at least four evolved Node Bs (eNBs) exist nearby or when all eNBs have the same height. Therefore, in this paper, we propose a new 3D positioning method that estimates the 3D coordinates of a user using three types of two-dimensional (2D) TDOAs. However, the give inaccurate results owing to the undefined axis of the 2D coordinate plane. Therefore, we propose a novel derivation of the hyperbola equation, which includes the undefined axis coordinate in the 2D hyperbola equation. Then, we propose an interaction algorithm that mutually supplies the undefined axis coordinate of users among 2D TDOAs. By performing extensive simulations, we verify that the proposed method is the only solution applicable by using three eNBs with different heights.

• Journal of the Ergonomics Society of Korea
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• v.29 no.4
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• pp.533-540
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• 2010

This study was to suggest the proper level of touch sensibility for twenties while flicking touch phones. A rapid prototype of $480{\times}800$ pixel size was developed for the experiment. Participants were 20 undergraduates, not visually and physically handicapped in using touch phones. 15 different modes, with each mode changing in velocity when flicking the prototype were randomly presented to each subject. The subjects were asked to score what they felt in each mode on a 1-to-6 Likert scale. The data was analyzed by the one-way ANOVA procedure. Each mode showed significant differences in 8 representative emotions except for exclusivity feeling and fresh feeling. Each velocity mode was scaled by the multidimensional scaling technique. Then, vector coordinates in each emotion were obtained by simple regression analysis. 15 velocity modes and each emotion were joint-plotted by the MDS, PROXSCAL. The findings in this study could be basic data for studying affective touch sensibilities in multiple ways.

• The Journal of Korean Association of Computer Education
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• v.16 no.3
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• pp.31-39
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• 2013

We developed a smart learning system by using the 'bring your own device' concept, which means the policy of permitting teacher and learners to bring personally owned mobile devices such as laptops, tablets, smart phones, etc. and applied the system to school classes. In addition, we analyzed the learner's satisfaction related to interfaces, interactions, applications, technical support, and evaluation areas. The evaluation system consists of App program for tablet PC's and smartphones, web program for desktop PC and electronic teaching desk, and server program for evaluation and database. Because all the teaching materials, feedback data and evaluation materials about learners are stored on the server, students can receive the necessary data through real-time feedback using their smartphones and desktop PC's. As a result, it could increase educational achievement with interest in learning.

• Journal of the Korean Society of Costume
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• v.65 no.7
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• pp.101-117
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• 2015

Along with the development of overall internet service, online fashion communities appeared and have started to thrive. The growth of mobile service has led to an even bigger expansion of these communities, and will wield a strong influence for the foreseeable future. The purpose of our study is to investigate the relationship between the behavior of these fashion communities and personality characteristics of the community features. For our data analysis, our study used 302 men and women, aged from their 20's and their 40's. The study results are as follows: First, some features, such as interaction, entertainment, promotion, information, and system technique, were drawn as the factors of the online fashion communities. Second, we could divide the community behavioral types into three different groups: buyer, maven, and onlooker groups. Third, all three groups showed different community characteristics. The primary concern for the buyer group was promotion while the mavens and the on-lookers were most interested in information. Fourth, they also showed different demographic characteristics in terms of gender, age, duration of membership, on-line time per visit and number of visits per week. These results show that a new strategy is necessary for online fashion communities to differentiate themselves and their marketing to consumers and their community behavioral types.

• The Journal of the Korea Contents Association
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• v.20 no.2
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• pp.114-126
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• 2020

With the growth of information technology, people consume online video contents via mobile phone without time and location constraints. Drawing upon uses and gratification theory, this study examines the effects of usage motives and affinity on user activities on YouTube. Specifically, user activities are subdivided into pre-viewing and during-viewing activities in this study. Results show that convenient entertainment and social interaction are the significant indicators for pre-viewing activities, whereas five different motives significantly influence during-viewing activities. Furthermore, affinity is the significant determinant of the both activities. The theoretical and practical implications are also discussed.

• Proceedings of the Korea Information Processing Society Conference
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• 2005.05a
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• pp.201-204
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• 2005

현재의 세계적인 트렌드인 HCI(Human Computer Interaction)에서 사용자의 기호나 의견 등을 반영하는 인터렉티브 미디어(Interactive Media)는 빠질 수 없는 주제다. 본 연구팀은 모바일 단말환경에서 사용자의 인터렉션을 통한 서비스를 제공할 수 있는 IMS(Interactive Media System)를 설계하고, 이를 PDA 상에 구현하였다. 기존의 연구들이 보여주는 링크의 형태로만 미디어를 지원하는 방식은 CPU 등의 자원이 부족한 모바일 환경에서는 부담이 될 수 있다. IMS 는 이를 벗어나 내부적으로 미디어 오브젝트를 지원하는 방식을 사용하여 모바일 환경에 적합하게 연산속도를 개선하고 있다. 또한 이러한 방식으로 인하여 생길 수 있는 문제인 미디어 포맷의 지원에 대한 제약을 극복하기 위해 확장성 있는 구조로 설계되어 이미지와 텍스트, 백터그래픽 만을 제공하던 단순한 시스템에서 H.264 와 MPEG4 AAC 와 같은 여러 모듈들이 더해졌다. 또한 OpenGL 모듈이 추가되고 3D 오브젝트들이 새롭게 정의됨으로써 IMS 는 IML 을 통해 마크업 언어차원에서 3D 그래픽을 지원할 수 있게 되었고 2D 와 3D 를 함깨 사용한 다양한 비쥬얼 구성이 가능하게 되었다. 본 논문에서는 IMS 의 확장성 있는 구조와 OpenGL 을 추가하고 새로운 미디어 오브젝트를 정의하는 과정 등을 다루며 언급한 내용을 자세히 소개한다.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1996.06c
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• pp.142-159
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• 1996

Engineering of automated tools for the agro-food industries and the rural world activities have to pick up two challenges : to answer the immediate important problems related to the situation of these industries, and to imaging the tools that their professional will need next century. Creating or modifying automated tools in the next few will be made taking into account parameters either technical (environmental protection, health and safety), or social and economical (investment , employment). There will be a strong interaction with disciplines like ecology, medicine, ergonomy, psycho-sociology , etc. , The partners for such a research, tools manufactures and users, should have an early involvement in its content, in order to find rapidly the solution to the drastic problems they are meeting. On a longer term , during the next 20 years , there will be an important evolution of the rural space management and of the food processes. This will imply the emergence of new types of activities and know-how's , with lines of automated tools to be invented and developed , like : micro-system for organic localized tasks -mobile and adaptive equipments highly autonomous for natural space actions - device for perception , decision and control reproducing automatically the expert behaviors of human operators. Design of such automated tools need to overcome technological difficulties like the automation of the expert-decision process, or the management of complex design.

• Mass Spectrometry Letters
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• v.11 no.1
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• pp.10-14
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• 2020

Riboflavin is a water-soluble vitamin, which serves as a precursor to flavin mononucleotide and flavin adenine dinucleotide. This study aimed to develop a simple and rapid liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis for the quantification of riboflavin in the Beagle dog plasma. This method utilized simple protein precipitation with acetonitrile and ¹³C₄, ¹⁵N₂-riboflavin was used as an internal standard (IS). For chromatographic separation, a hydrophilic interaction liquid chromatography (HILIC) column was used with gradient elution. The mobile phase consisted of 0.1% (v/v) aqueous formic acid with 10 mM ammonium formate and acetonitrile with 0.1% (v/v) formic acid. Since riboflavin is an endogenous compound, 4% bovine serum albumin in phosphate buffered saline was used as a surrogate matrix to prepare the calibration curve. The quantification limit for riboflavin in the Beagle dog plasma was 5 ng/mL. The method was fully validated for its specificity, sensitivity, accuracy and precision, recovery, and stability according to the US FDA guidance. The developed LC-MS/MS method may be useful for the in vivo pharmacokinetic studies of riboflavin.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.11
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• pp.4103-4117
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• 2014

Image processing and computer vision algorithms are gaining larger concern in a variety of application areas such as robotics and man-machine interaction. Vision allows the development of flexible, intelligent, and less intrusive approaches than most of the other sensor systems. In this work, we determine the location and orientation of a mobile robot which is crucial for performing its tasks. In order to be able to operate in real time there is a need to speed up different vision routines. Therefore, we present and evaluate a method for introducing parallelism into the multiple non-overlapping camera pose estimation algorithm proposed in [1]. In this algorithm the problem has been solved in real time using multiple non-overlapping cameras and the Extended Kalman Filter (EKF). Four cameras arranged in two back-to-back pairs are put on the platform of a moving robot. An important benefit of using multiple cameras for robot pose estimation is the capability of resolving vision uncertainties such as the bas-relief ambiguity. The proposed method is based on algorithmic skeletons for low, medium and high levels of parallelization. The analysis shows that the use of a multiprocessor system enhances the system performance by about 87%. In addition, the proposed design is scalable, which is necaccery in this application where the number of features changes repeatedly.

• Journal of Korea Game Society
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• v.16 no.3
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• pp.87-96
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• 2016

As use of Internet increase, IoT(Internet Of Things), a interaction between connected devices, is widely used throughout industrial area. In this paper, we discussed what to consider when planning framework for contents using user's mobile devices and various sensors in IoT environment and suggest related techniques. Also, using the techniques suggested in this paper, we showed the prototype of the framework. Finally, we showed the possibility of games in the IoT environment by creating game in the IoT environment.