• Proceedings of the Korean Society of Computer Information Conference
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• 2022.01a
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• pp.377-380
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• 2022

본 논문에서는 모바일 기반 AR 환경에서 RGB카메라로부터 얻은 영상 분석과 DB 기반의 특징점(Feature point) 매칭을 통하여 보다 정확하게 위험 상황을 알려줄 수 있는 프레임워크를 제안한다. 본 논문에서는 RANSAC(Random sample consensus)기반의 다중 평면 방식을 이용한 특징점을 추출하고 분석하여 영상에 존재하는 장애물을 감지한다. RGB카메라로 얻은 영상을 기반으로 장애물을 검출하는 접근법은 영상에 의존하기 때문에 조명에 따른 특징점 검출이 부정확하고, 조명이나 자연광 또는 날씨에 영향을 많이 받기 때문에 어둡거나 흐린 날씨에서는 장애물 검출이 어려워진다. 이 문제를 완화하기 위해 본 논문에서는 DB기반의 특징점 매칭을 통해 조명에 관계없이 장애물을 효율적이고 정확하게 감지한다. 특징점 매칭을 이용하려면 우선 영상에서 특징점이 안정적으로 추출될 수 있는 환경인, 조명이나 자연광이 충분한 환경에서 감지된 장애물 정보를 데이터베이스화 하여 저장한다. 조명이 충분하지 않은 환경에서 사용자가 사전에 저장된 지역에 근접할 경우 특징점 분석이 아닌 DB 기반 특징점 매칭을 통해 위험 요소를 감지한다. 우리의 방법은 조명의 여부의 관계없이 효과적으로 위험을 감지할 수 있기 때문에 다양한 분야에 활용될 수 있다.

• The Journal of Society for e-Business Studies
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• v.21 no.1
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• pp.65-77
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• 2016

As respecting one's privacy becomes an important issue in mobile device data analysis, on-device analysis is getting attention, in which the data analysis is conducted inside a mobile device without sending data from the device to outside. One possible application of the on-device analysis is gender prediction using text data in mobile devices, such as text messages, search keyword, website bookmarks, and contact, which are highly private, and the limited computing power of mobile devices can be addressed by utilizing the word comparison method, where words are selected beforehand and delivered to a mobile device of a user to determine the user's gender by matching mobile text data and the selected words. Moreover, it is known that performing prediction after filtering instances using definite evidences increases accuracy and reduces computational complexity. In this regard, we propose a two-phase approach to on-device gender prediction, where both discriminability and popularity of a word are sequentially considered. The proposed method performs predictions using a few highly discriminative words for all instances and popular words for unclassified instances from the previous prediction. From the experiments conducted on real-world dataset, the proposed method outperformed the compared methods.

• KIPS Transactions on Software and Data Engineering
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• v.2 no.8
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• pp.507-516
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• 2013

Mobile devices have limited computing power and resources. Since mobile devices are equipped with rich network connectivity, an approach to subscribe cloud services can effectively remedy the problem, which is called Mobile Cloud Computing (MCC). Most works on MCC depend on a method to offload functional components at runtime. However, these works only consider the limited verion of offloading to a pre-defined, designated node. Moveover, there is the limitation of managing services subscribed by applications. To provide a comprehensive and practical solution for MCC, in this paper, we propose a self-stabilizing process and its management-related methods. The proposed process is based on an autonomic computing paradigm and works with diverse quality remedy actions such as migration or replicating services. And, we devise a pratical offloading mechanism which is still in an initial stage of the study. The proposed offloading mechanism is based on our proposed MCC meta-model. By adopting the self-stabilization process for MCC, many of the technical issues are effectively resolved, and mobile cloud environments can maintain consistent levels of quality in autonomous manner.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.7A
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• pp.493-502
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• 2003

In this paper, to solve some problems of the Mobile IP and local registration strategy we propose a method that can effectively support real-time traffics sensitive to delay time and packet loss. The proposed method reduces the registration time after a Mobile Node's movement between networks by carrying out the pre-registration for the domain which it will move into the network information of the link layer of cdma2000 system, at the boundary cell's handoff zone. Through the cost analysis and simulation it is shown that the proposed scheme yield a better performance compared with the Mobile IP and local registration strategies in terms of packet loss for parameters; variation of the velocity of a Mobile Node, and a distance between the Mobile Node and home networks, etc.

• Journal of Korea Game Society
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• v.17 no.2
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• pp.135-144
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• 2017

Sentiment analysis refers to a way of analyzing the writer's subjective opinions or feelings through text. For effective sentiment analysis, it is essential to build emotional word polarity lexicon. This paper introduces a crowdsourcing-based game that we have developed for efficiently building a polarity lexicon in Korean. First, we collected a corpus from the relating Internet communities using a crawler, and we classified them into words using the Twitter POS analyzer. These POS-tagged words are provided as a form of mobile platform based tagging game in which the players voluntarily tagged the polarities of the words, and then the result was collected into the database. So far we have tagged the polarities of about 1200 words. We expect that our research can contribute to the Korean sentiment analysis research especially in the game domain by collecting more emotional word data in the future.

• Korean journal of communication and information
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• v.79
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• pp.140-164
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• 2016

What is an appropriate length of an article in the mobile era producing new tastes of contents combining computing and mobile communication? Is it still valid to have a lengthy article as high level journalism even in the mobile era? Is there any possibility to have a short article combination to give us readability and the amount of information? This study aims to find some answers to these questions. The length of articles were controlled with a field experiment; from an article of 346 syllables(including spaces between syllables) which does not need finger scrolling on a mobile phone to articles of 633, 1033, 1368 syllables(including spaces between syllables) which frequently appear in newspapers and broadcasting news program. All the main themes were same for 4 articles which have different length. Three hundred and eighty four students viewed one of the 4 articles through mobile phone or newspaper. Each participant checked their preference and evaluated quality on the article, were asked to recall contents of the article. In newspaper group, articles with 346 or 1033 syllables were highly evaluated. Mobile group seemed to prefer articles of 346 or 633 syllables. In conclusion, we need to consider various strategies shortening the length of an article into 346 or 633 syllables as a basic format to meet the neEds of mobile era.

• Journal of Digital Convergence
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• v.18 no.6
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• pp.287-295
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• 2020

This study defined the characteristics of micro-learning emerging by mobile learning and micro-contents in the e-learning field, and analyzed the satisfaction of application, to see if micro-learning could become a new learning type in the future. To this end, the characteristics of micro-learning were defined through preliminary literature analysis, the characteristic satisfaction was verified in the well-equipped micro-learning site, and any other technical functions were suggested through expert opinion gathering. It was suggested that the future technology of e-learning should be linked to technical functions such as learning analysis and performance measurement. According to the results of this study, if micro-learning reflects its functional characteristics well, it will become an effective learning type in the e-learning field and will greatly contribute to education, learning, and training for the new millennial.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.8
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• pp.77-86
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• 2014

Mobile devices are generally using app images which are artificially designed. Accordingly, this paper presents adjusting device brightness based on app image categorization for enhancing the visibility under various light condition. First, the proposed method performed two prior subjective tests under various lighting conditions for selecting features of app images concerning visibility and for selecting satisfactory range of device brightness for each app image. Then, the relationship between selected features of app image and satisfactory range of device brightness is analyzed. Next, app images are categorized by using two features of average brightness of app image and distribution ratio of advanced colors that are related to satisfaction range of device brightness. Then, optimal device brightness for each category is selected by having the maximum frequency of satisfaction device brightness. Experimental results show that the categorized app images with optimal device brightness have high satisfaction ratio under various light conditions.

• The Journal of Society for e-Business Studies
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• v.11 no.2
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• pp.111-134
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• 2006

This paper analyzes the resistance to mobile commerce services in consumer adoption process. Relative advantage, compatibility, perceived risk, complexity, self-efficacy, innovativeness and attitude for competing service have been chosen as independent variables. This paper also investigates on the significant factors which resist against adoption of mobile commerce service according to adoption phase. The results show that relative advantage, self-efficacy, perceived risk, attitude for competing service are significant factors to affect resistance to mobile commerce services. Relative advantage, perceived risk, attitude for competing service are significant resistance to mobile commerce services for consumers in before-adoption group and compatibility, complexity, self-efficacy are significant factors for consumers in after-adoption group. This study can be extended to new communication services such as Wibro and DMB to reduce resistances in early adoption phase.

• Journal of Navigation and Port Research
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• v.34 no.8
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• pp.629-634
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• 2010

Mathematical model of maneuvering motion for a Mobile Harbor is established and versatile applications to the special situations of maneuvering are attempted. The Mobile Harbor in this research has twin Azipod thruster and twin bow thruster. In order to predict the maneuverability of Mobile Harbor, a mathematical model was developed on the basis of MMG model, and some model test results were adopted for the simulation of Mobile Harbor. As a result, the turning motions of the Mobile Harbor were successfully calculated. and the optimal berthing system was completed.