• Journal of Advanced Navigation Technology
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• v.12 no.2
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• pp.154-163
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• 2008

In a mobile broadband wireless access (MBWA) network, many users access a base station (BS), which relays data transferred from high-speed wired network to low-speed wireless network. For this difference of their data rate, a BS suffers from the lack of its buffer space when many users run multiple applications at the same time, and thus packet losses occur. TCP, which guarantees end-to-end reliability, is used as transport protocol also in wireless networks. But TCP lowers their transmission rate incorrectly and frequently whenever packet losses occur. And they increase their transmission rate differently with each other; finally TCP throughput of each TCP flow varies largely, and then TCP fairness goes worse. In this paper, a scheme that controls packet transmission rate adaptively according to TCP flows' transmission rate, that prevents buffer overflows at BS, and that guarantees TCP fairness at a certain degree is proposed. As it is analyzed by simulations, the proposed scheme enhances TCP fairness by maintaining TCP throughput of each TCP sender similarly with each other.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.36 no.2
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• pp.39-48
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• 2013

The development of mobile communication technology is transforming the market of mobile communication devices, which is used to be merely for simple communication, into the one which offers features of personal digital assistant (PDA), fax communication and Internet access. Unlike a mobile phone which comes out as a complete package and whose functions cannot be changed, a smart phone can be upgraded by its user, adding or removing apps as he pleases. OS's of smart phones are iOS-based Apple, Google Android, Window Mobile, and others. Due to its convenience and powerful features, many people use smart phones its high price. On the other hand, consumer complaints are rising on poor A/S for occasional malfunction. This study analyzes how A/S cases can be classified into groups according to quality factors. We evaluate factors such as consumer impression and consumer satisfaction. By dual quality evaluation using KANO method, we would like to show the different A/S strategy for smart phones, compared with mobile phones.

• Journal of the Institute of Convergence Signal Processing
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• v.15 no.3
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• pp.76-79
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• 2014

Face recognition is very challenging because of the unexpected changes of pose, expression, and illumination. Facial detection in the mobile environments has additional difficulty since the computational resources are very limited. This paper discusses face detection based on frequency domain matched filtering in the mobile environments. Face detection is performed by a linear or phase-only matched filter and sequential verification stages. The candidate window regions are selected by a number of peaks of the matched filtering outputs. The sequential stages comprise a skin-color test and an edge mask filtering tests, which aim to remove false alarms among selected candidate windows. The algorithms are built with JAVA language on the mobile device operated by the Android platform. The simulation and experimental results show that real-time face detection can be performed successfully in the mobile environments.

• Journal of Intelligence and Information Systems
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• v.20 no.3
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• pp.1-18
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• 2014

Over the past years RFID/SN has been an elementary technology in a diversity of applications for the ubiquitous environments, especially for Internet of Things. However, one of obstacles for widespread deployment of RFID technology is the inherent unreliability of the RFID data streams by tag readers. In particular, the problem of false readings such as lost readings and mistaken readings needs to be treated by RFID middleware systems because false readings ultimately degrade the quality of application services due to the dirty data delivered by middleware systems. As a result, for the higher quality of services, an RFID middleware system is responsible for intelligently dealing with false readings for the delivery of clean data to the applications in accordance with the tag reading environment. One of popular techniques used to compensate false readings is a sliding window filter. In a sliding window scheme, it is evident that determining optimal window size intelligently is a nontrivial important task in RFID middleware systems in order to reduce false readings, especially in mobile environments. In this paper, for the purpose of reducing false readings by intelligent window adaption, we propose a new adaptive RFID data cleaning scheme based on window sliding for a single tag. Unlike previous works based on a binomial sampling model, we introduce the weight averaging. Our insight starts from the need to differentiate the past readings and the current readings, since the more recent readings may indicate the more accurate tag transitions. Owing to weight averaging, our scheme is expected to dynamically adapt the window size in an efficient manner even for non-homogeneous reading patterns in mobile environments. In addition, we analyze reading patterns in the window and effects of decreased window so that a more accurate and efficient decision on window adaption can be made. With our scheme, we can expect to obtain the ultimate goal that RFID middleware systems can provide applications with more clean data so that they can ensure high quality of intended services.

• The Journal of Korea Robotics Society
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• v.3 no.3
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• pp.212-218
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• 2008

Collision avoidance is a fundamental and important task of an autonomous mobile robot for safe navigation in real environments with high uncertainty. Obstacles are classified into static and dynamic obstacles. It is difficult to avoid dynamic obstacles because the positions of dynamic obstacles are likely to change at any time. This paper proposes a scheme for vision-based avoidance of dynamic obstacles. This approach extracts object candidates that can be considered moving objects based on the labeling algorithm using depth information. Then it detects moving objects among object candidates using motion vectors. In case the motion vectors are not extracted, it can still detect the moving objects stably through their color information. A robot avoids the dynamic obstacle using the dynamic window approach (DWA) with the object path estimated from the information of the detected obstacles. The DWA is a well known technique for reactive collision avoidance. This paper also proposes an algorithm which autonomously registers the obstacle color. Therefore, a robot can navigate more safely and efficiently with the proposed scheme.

• Journal of Korea Society of Digital Industry and Information Management
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• v.11 no.2
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• pp.153-166
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• 2015

This paper proposes a trans-media branding for the trans-media-based cultural content marketing strategy. Trans-media brand analytical framework is proposed with previous studies. And mobile messenger Character 'Line Friends' is analyzed for the text. Trans-media branding is accessible through a multi-platform in the technological environment. Consumer culture, as well as participate include business models to generate revenue also as brand equity. While the character elements that make up the story from the perspective of cultural content storytelling act as an independent cultural goods. Character is segmented elements. Therefore, trans- media branding of the characters are more meaningful. 'Line Friends' trans-media branding can be summarized as follows: First, it takes advantage of the characteristics of the existing Information-Technology-based mobile. Second, it puts consistently found the content of the attributes of Mobile Messenger 'communication' and 'friendship'. And third, while the content of each platform is constantly linked with other platforms, the brand is positioned inside the window effect.

• Proceedings of the IEEK Conference
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• 2001.09a
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• pp.841-844
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• 2001

This paper introduces a new technique for estimating the speed of a mobile station in a wireless system. The proposed method is based on the feature extraction of the received signal envelope. The undecimated discrete wavelet transform via lifting captures local minimum points of the received signal, which is used for the speed estimation. This technique requires neither knowledge of the average received power of the nonstationary signal nor adaptation of a temporal observation window, in contrast to other speed estimators given in the literature. Simulations show that the proposed speed estimator tracks the variable speed of the mobile station.

• International Commerce and Information Review
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• v.3 no.2
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• pp.177-192
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• 2001

전자상거래의 탄생과 성장의 가장 큰 당위성은 고객의 만족도 제고와 효용성의 증대라 할 수 있다. 이러한 측면에서 살펴볼 때, 이동성, 위치성, 접근성 및 개인성을 고루 갖춘 M-Commerce에 대한 수요는 매우 폭발적일 것으로 판단된다. 그럼에도 불구하고 기존의 유선 인터넷 망을 이용하는 전자상거래에 비해 기술 규격이 표준화되지 못하고 있는 점, 보안 및 인중이 취약하다는 점, 불편한 인터페이스 등의 문제로 아직까지는 대중화되지 못하는 태동기라고 볼 수 있다. 현재, M-Commerce의 주요 수단으로 사용되는 Cellular Phone과 PCS의 차기 모델로서 대두되고 있는 IMT 2000과 기존의 단말기를 대체하는 PDA 사용자의 급증 동 제반 불만족 요인의 상당 부분을 극복 할 수 있을 것으로 판단된다. 또한, M-Commerce의 Business Model은 기존은 기존의 전자상거래가 B2B 시장이 가장 폭넓은 시장인데 비해 B2C 시장으로 특화될 수 있을 것으로 전망된다.

• Fashion & Textile Research Journal
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• v.18 no.6
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• pp.825-832
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• 2016

The purposes of this study was to investigate effects of fashion brand apps on smartphones flow and consumer satisfaction in mobile shopping. These findings provide new information to marketers for the marketing strategy for dealing with mobile shopping mall. A total of 233 usable questionnaires were obtained from men and women ages 20-30 who have mobile shopping purchasing experience. Data were analyzed by frequency analysis, factor analysis using SPSS for Window 22.0 and confirmatory factor analysis and structural equation model analysis by AMOS 22.0. The results were as follows. First, the analysis of fashion brand apps factors showed that it consist of 2 kinds of dimensions of basic information type and additional information type. Second, basic information type of fashion brand apps have had a direct impact on consumer satisfaction and did not affect the smartphones flow. Additional information type influence consumer satisfaction through a smartphones flow. Basic information type of fashion brand apps showed a greater impact on consumer satisfaction than a smartphone flow. A managerial implication was discussed for fashion brand marketers to develop strategies on fashion brand apps that could stimulate and increase the consumer flow and satisfaction.

• Journal of East-West Nursing Research
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• v.24 no.2
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• pp.119-129
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• 2018

Purpose: The aim of this study was to examine the effect of providing information using a mobile internet terminal on anxiety, discomfort and satisfaction with education among patients undergoing a coronary angiogram. Methods: Data were collected from July 27, 2016 to February 23, 2017. A total of 64 participants (34 for the experiment group and 30 for the control group) admitted to a department of cardiology internal medicine for coronary angiography were recruited. Data were analyzed by SPSS Window 22.0 Program. Results: Information provided through mobile internet terminal did not affect anxiety and objective and subjective discomfort of the participants for coronary angiography, it was effective in satisfaction with education. Conclusion: Based on the results, it is indicated that video education using a mobile internet terminal could be an effective method to improve nurses' work efficiency and quality and to raise satisfaction with education.