• 디지털융복합연구
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• 제9권1호
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• pp.115-124
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• 2011

The property of the mobile phone is taking important role to choose it. In the present situation, exploring, comparing and analyzing the important properties of regular mobile phone(feature phone) and smart phone are very meaningful study. Therefore, the survey was carried out to get the properties of feature phone and smart phone and analyze the difference of those phones. And proposed the important variables for customer satisfaction which must be given priority. The result showed that 'design' and 'Quality' are important to both mobile phone user groups. The problems with mobile phones currently in use were 'poor performance' to feature phone users and 'expensive charge' and 'poor A/S' to smart phone users. Two groups also showed significant difference with the customer satisfactions, and smart phone user group showed higher satisfaction. For smart phone user group, four factors are induced from the properties but 'Hardware Quality' (representing 'call Quality', 'A/S', 'Convenience to use', 'Battery life') and 'Design & Function'(representing 'Internet', 'Convergence Functions', 'Design, 'Color') have significant and positive effects on Customer Satisfaction.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권12호
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• pp.5087-5102
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• 2015

Rapid popularization of smart cell phone equipped with camera has led to a number of new legal and criminal problems related to multimedia such as digital image, which makes cell phone source identification an important branch of digital image forensics. This paper proposes a classifier combination based source identification strategy for cell phone images. To identify the outlier cell phone models of the training sets in multi-class classifier, a one-class classifier is orderly used in the framework. Feature vectors including color filter array (CFA) interpolation coefficients estimation and multi-feature fusion is employed to verify the effectiveness of the classifier combination strategy. Experimental results demonstrate that for different feature sets, our method presents high accuracy of source identification both for the cell phone in the training sets and the outliers.

• 디지털산업정보학회논문지
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• 제9권1호
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• pp.25-31
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• 2013

Medication adherence is a basic and important element in diabetes management, and it has been known the adherence rate should be keep over 80% to get positive result in diabetes management. In order to increase medication adherence, there have been smart phone apps that record medication, exercise, and diet. However, diabetes patients are generally over 50s, and most of them do not use smart phones. Therefore, in this paper, we propose a medication adherence help system that support both smart phone apps and feature phone SMS. Furthermore, we introduce system architecture for the system. Our work will help ICT-based diabetic management system developers to consider some issues for mobile based diabetic management systems..

• 한국컴퓨터정보학회논문지
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• 제22권9호
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• pp.65-71
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• 2017

This paper proposes a smart phone authentication method based on user's behavior and habit that is an authentication method against shoulder surfing attack and brute force attack. As smart phones evolve not only storage of personal data but also a key means of financial services, the importance of personal information security in smart phones is growing. When user authentication of smart phone, pattern authentication method is simple to use and memorize, but it is prone to leak and vulnerable to attack. Using the features of the smart phone pattern method of the user, the pressure applied when touching the touch pad with the finger, the size of the area touching the finger, and the time of completing the pattern are used as feature vectors and applied to user authentication security. First, a smart phone user models and stores three parameter values as prototypes for each section of the pattern. Then, when a new authentication request is made, the feature vector of the input pattern is obtained and compared with the stored model to decide whether to approve the access to the smart phone. The experimental results confirm that the proposed technique shows a robust authentication security using subjective data of smart phone user based on habits and behaviors.

• 한국HCI학회:학술대회논문집
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• 한국HCI학회 2008년도 학술대회 1부
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• pp.120-124
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• 2008

본 사례연구의 사례는 휴대폰의 주된 용도인 커뮤니케이션 기능 외에 체중관리, 식이요법관리를 중심으로 지압, 요가 가이드 등을 묶은 웰빙 기능을 휴대전화에 구현한 과정이다. 휴대전화는 항상 휴대하고 다니는 기기라는 점 때문에 이러한 사용자 개인의 사생활 정보를 관리하기에 적합한 장점을 가지며 특히 개인화 되는 트랜드에 따라 통신 외적인 새로운 기능들이 다양하게 개발되게 되었다. 본 사례연구에서는 실용성 있고 실제 사용자의 생활에 더욱 더 밀접하게 개발하기 위한 방법으로 라이프 스타일을 연구를 통해 20 대 후반의 직장여성을 페르소나로 설정하여 이에 따라 만들어진 시나리오에 의해 어떠한 기능이 필요할 것인지 결정하고 필요한 콘텐츠를 만들었다. 이러한 사례를 통해 휴대전화가 향후 어떻게 개인화 된 콘텐츠를 제공하고 적절한 사용성을 가진 기능으로 이 콘텐츠를 이용할 수 있는지에 대한 사용자 중심적 디자인의 실제적 사례를 제시하고 향후 보다 개인화 된 기능을 개발 하기 위한 지침으로 제시하고자 한다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제6권11호
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• pp.2849-2865
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• 2012

In order to block mobile junk messages automatically, many studies on spam filters have applied machine learning algorithms. Most previous research focused only on the accuracy rate of spam filters from the view point of the algorithm used, not on individual user's preferences. In terms of individual taste, the spam filters implemented on a mobile device have the advantage over spam filters on a network node, because it deals with only incoming messages on the users' phone and generates no additional traffic during the filtering process. However, a spam filter on a mobile phone has to consider the consumption of resources, because energy, memory and computing ability are limited. Moreover, as time passes an increasing number of feature words are likely to exhaust mobile resources. In this paper we propose a spam filter model distributed between a users' computer and smart phone. We expect the model to follow personal decision boundaries and use the uniform resources of smart phones. An authorized user's computer takes on the more complex and time consuming jobs, such as feature selection and training, while the smart phone performs only the minimum amount of work for filtering and utilizes the results of the information calculated on the desktop. Our experiments show that the accuracy of our method is more than 95% with Na$\ddot{i}$ve Bayes and Support Vector Machine, and our model that uses uniform memory does not affect other applications that run on the smart phone.

• ETRI Journal
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• 제41권2호
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• pp.235-241
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• 2019

In this paper, we propose a rank-weighted reconstruction feature to improve the robustness of a feed-forward deep neural network (FFDNN)-based acoustic model. In the FFDNN-based acoustic model, an input feature is constructed by vectorizing a submatrix that is created by slicing the feature vectors of frames within a context window. In this type of feature construction, the appropriate context window size is important because it determines the amount of trivial or discriminative information, such as redundancy, or temporal context of the input features. However, we ascertained whether a single parameter is sufficiently able to control the quantity of information. Therefore, we investigated the input feature construction from the perspectives of rank and nullity, and proposed a rank-weighted reconstruction feature herein, that allows for the retention of speech information components and the reduction in trivial components. The proposed method was evaluated in the TIMIT phone recognition and Wall Street Journal (WSJ) domains. The proposed method reduced the phone error rate of the TIMIT domain from 18.4% to 18.0%, and the word error rate of the WSJ domain from 4.70% to 4.43%.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제6권3호
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• pp.835-854
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• 2012

In this paper, we propose a novel positioning system for indoor navigation which helps a user navigate easily to desired destinations in an unfamiliar indoor environment using his mobile phone. The system requires only the user's mobile phone with its basic equipped sensors such as a camera and a compass. The system tracks user's positions and orientations using a vision-based approach that utilizes $360^{\circ}$ panoramic images captured in the environment. To improve the robustness of the vision-based method, we exploit a digital compass that is widely installed on modern mobile phones. This hybrid solution outperforms existing mobile phone positioning methods by reducing the error of position estimation to around 0.7 meters. In addition, to enable the proposed system working independently on mobile phone without the requirement of additional hardware or external infrastructure, we employ a modified version of a fast and robust feature matching scheme using Histogrammed Intensity Patch. The experiments show that the proposed positioning system achieves good performance while running on a mobile phone with a responding time of around 1 second.

• 경영과정보연구
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• 제32권2호
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• pp.83-106
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• 2013

본 연구는 컨버전스 제품의 대표격인 스마트폰을 대상으로 해당 스마트폰에서 광고의 양, 하드웨어 다양성, 소프트웨어의 다양성 등이 스마트폰에 대한 유용성 지각과 복잡성 지각에 동시에 영향을 줄 수 있고 복잡성은 기능적 피로에 영향을 미칠 수 있다는 것을 검증하려고 하였다. 먼저, 소비자가 모바일 광고를 과다하다고 느낄수록 스마트폰의 유용성을 낮추고 복잡성을 높인다는 것은 검증되지 못하였지만 하드웨어의 다양성은 유용성을 높이고 복잡성을 높게 지각하게 만들 것이라는 가설은 강하게 지지되었다. 몇번 논의되었듯이 컨버전스의 가장 기본은 상당히 많은 하드웨어의 통합이다. 결국, 많은 하드웨어는 스마트폰의 효용가치를 높이는 중요한 원인이 되기도 하지만 동시에 복잡성을 높여 소비자에게 스마트폰을 이용하는데서 피로를 유발하는 원인으로 작용할 수도 있다는 결론이다. 소프트웨어의 다양성은 유용성을 높게 지각하게 만드는 요소이기는 하나 복잡성에는 별다른 영향을 미치지 못하는 것으로 나타났다. 유용한 모바일 앱을 많이 제공하는 것은 역시 하나의 매력적인 요소로 작용할 수 있다고 결론지었다. 마지막으로 복잡성은 기능적 피로를 높게 지각하는데 영향을 미치는 중요한 요인으로 밝혀졌으며 결국, 이는 무조건 많다고 좋은 것이 아니라 최적의 컨버전스 조합을 찾는 것이 바람직하다는 시사점을 제시할 수 있다.

• 대한원격탐사학회지
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• 제24권3호
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• pp.245-250
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• 2008

According to public and industrial interests on mobile graphics, a preliminary implementation regarding 3D feature visualization system on cell phone was performed using M3G API, one of the de-facto standards for mobile 3D graphic API. Through this experiment, it is revealed that scene graph structure and 3D mobile file format supported from this API is useful one for 3D geo-modeling and rendering in mobile environment. It is necessary that 3D mobile graphic standards can be considered as one component of current mobile GIS services standards to provide value-added 3D GIS contents.