• International Journal of Fuzzy Logic and Intelligent Systems
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• 제15권2호
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• pp.126-131
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• 2015

Studies on the control of inverted pendulum type systems have been widely reported. This is because this type of system is a typical complex nonlinear system and may be a good model to verify the performance of a proposed control system. In this paper, we propose the design of two fuzzy logic control systems for the control of a Segway mobile robot which is an inverted pendulum type system. We first introduce a dynamic model of the Segway mobile robot and then analyze the system. We then propose the design of the fuzzy logic control system, which shows good performance for the control of any nonlinear system. In this paper, we here design two fuzzy logic control systems for the position and balance control of the Segway mobile robot. We demonstrate their usefulness through simulation examples. We also note the possibility of simplifying the design process and reducing the computational complexity. This possibility is the result of the skew symmetric property of the fuzzy rule tables of the system.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.1166-1171
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• 2004

In this study, the concept of autonomous mobility is applied to a gait support mobile robot. The aim of the development of the service robot is to assist the elderly with gait rehabilitation. This study proposes an ergonomic service robot design parameter. The gait assistant path pattern is derived from analysis of the elderly gait. A lever is installed in the AMR in order to measure both the pulling force and the leading force of the elderly. The path generation of the mobile robot is developed through consideration and analysis of elderly gait patterns. The ergonomic design parameters (dimensions, action scope and working space) are determined based on moving scope of the elderly. The gait assistant mobile robot was offered the elderly guide service and internet service based on the ergonomic design parameters.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 하계종합학술대회 논문집 Ⅲ
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• pp.1677-1680
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• 2003

In this paper, we propose the multimedia tutoring system that provides multimedia learning contents for english Loaming on mobile environment. In order to design and implement the system, we have developed mobile multimedia contents from contents modeling based on the types of item, but also mobile interface to provide learning contents for learners effectively under limitation of mobile environment. The contents server in this system creates multimedia learning contents as XML document for each learner and provides those to learners through mobile interface using Wireless Application Protocol at anytime and anyplace.

• ETRI Journal
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• 제19권3호
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• pp.169-185
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• 1997

This paper presents the design concepts and the system architecture of a mobile exchange for CDMA Mobile System. The paper also discusses complex subsystems in this system and design concepts of these subsystems. To evaluate the performance of the CDMA Mobile System, we have performed a computer simulation based on the framework of the mobile exchange. Simulation results are presented in terms of network traffic load (call attempts per second) and database performance requirements (transactions per second.)

• 산업공학
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• 제20권4호
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• pp.539-546
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• 2007

This study has been conducted on touch screen interface design for mobile devices. It was intended to measure user’s satisfaction on one-handed thumb input mobile devices. Recent studies proposed the optimal touch button size, but it is inappropriate for mobile devices. Therefore, this study was focused on four touch key factors-width, height, the horizontal and vertical distance between touch keys-as independent variables. The ANOVA results showed that the user satisfaction of four touch key factors was significantly affected by the thumb input. It also apparent that the interactions between four factors were significant. As a result, the horizontal and vertical distance as well as the width and height affected the satisfaction of users. In addition, this study suggested satisfaction models which represent the top 30%, 50%, 70% of user satisfaction measurement. The results of this study could be used to design touch keys that are able to enhance the usability on touch screen based mobile devices.

• 한국컴퓨터정보학회논문지
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• 제7권4호
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• pp.16-23
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• 2002

최근 컴퓨터의 대용량화 및 고성능화에 따라 GIS에 근거한 다양한 형태의 연구 및 응용 시스템이 개발되고 있다. 또한, 점차적으로 PDA, HPC 등과 같은 Mobile 장치와 GPS와 같은 위치 추적 기술이 발전함에 따라 개인의 위치에 근거한 다양한 서비스가 제공되어지고 있다 이러한 Mobile GIS에서는 처리 능력이 낮은 Mobile 장치의 특성을 고려한 Mobile GIS를 위한 클라이언트의 개발이 필요하다. 이를 위하여, 본 연구에서는 Mobile GIS를 위한 클라이언트 인터페이스를 설계 및 구현하였다.

• 한국의상디자인학회지
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• 제22권3호
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• pp.139-153
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• 2020

Today, the proliferation of smart-phones and other mobile devices is bringing many changes to people's daily lives. Recently, the mobile shopping market has grown rapidly and has become a center of distribution. Furthermore, the consumer mobile fashion market is expected to expand and mobile fashion consumers' shopping tendencies will gradually become segmented. Differentiated marketing strategies for mobile fashion companies are to become essential. This study intends to understand the propensity of mobile fashion shopping and the importance of fashion app attributes, and their impact on mobile fashion shopping customer satisfaction and loyalty. The research aims to identify shopping trends and buying behaviors of mobile fashion consumers, find ways to increase mobile fashion shopping purchases, and help develop the mobile fashion market. The results of this study are summarized as follows. First, the compilation and the economics of the mobile fashion shopping propensity factors were shown to have a significant impact on product information, product reviews, and service quality, which are in turn important factors for fashion app attributes, whereas convenience only had a significant impact on service quality. Second, product information and service quality, which are also important factors for fashion app attributes, have a significant impact on mobile fashion shopping. Third, customer satisfaction concerning mobile fashion shopping has a significant impact on loyalty. Mobile fashion shopping customer satisfaction increases loyalty. Increasing the satisfaction and loyalty of mobile fashion shopping will lead to increased sales using mobile fashion shopping apps(Site) and become apparent in the results of mobile fashion companies. Therefore, various efforts by mobile fashion companies will be needed to satisfy their customers.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제15권4호
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• pp.232-239
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• 2015

Studies on the control of the inverted pendulum type system have been widely reported. This is because it is a typical complex nonlinear system and may be a good model for verifying the performance of a proposed control system. In this paper, we propose the design of some fuzzy logic control (FLC) systems for controlling a Segway-type mobile robot, which is an inverted pendulum type system. We first derive a dynamic model of the Segway-type mobile robot and then analyze it in detail. Next, we propose the design of some FLC systems that have good performance for the control of any nonlinear system. Then, we design two conventional FLC systems for the position and balance control of the Segway-type mobile robot, and we demonstrate their usefulness through simulations. Next, we point out the possibility of simplifying the design process and reducing the computational complexity,, which results from the skew symmetric property of the fuzzy control rule tables. Finally, we design two other FLC systems for position and balance control of the Segway-type mobile robot. These systems have only one input variable in the FLC systems. Furthermore, we observe that they offer similar control performance to that of the conventional two-input FLC systems.

• 디자인학연구
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• 제16권2호
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• pp.301-310
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• 2003

The interface design of mobile products has become a hot issue recently as a variety of products are being developed for extended usages. There have been two different views on interface design of mobile products like PDAs(personal digital assistants) or cellular phone. One 치aims that the current interface design of PC cannot be directly applied because mobile products have their own specific functions and requirements. On the meantime, the other argues that an extended application of PC metaphors to mobile products can have advantages because users'PC experiences can reduce the learning efforts and thus contribute to intuitive understanding mobile products. In this research, two types of PDAs, developed according to the aforementioned conflicting philosophies were compared and evaluated, based on laboratory-based usability testing conducted by novice users. The experiment consists of asking subjects to perform identical tasks for the two different types of products. The interaction data collected during usability testing were analyzed in terms of time taken, rate of success of tasks and errors. The experiment shows that there were some meaningful effects of users'experience of PC on the usability of PDAs.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 추계종합학술대회 논문집(1)
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• pp.469-472
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• 2000

Security-related issues in mobile communications are increasing. The security requirements of mobile communications for the mobile users include authentication of the mobile user, the data confidentiality, the data confidentiality and the location privacy of mobile user. These services require security features compatible with the wireline networks. However, wireless networks have many restrictions compare to wireline networks such as the limited computational capability of mobile equipment and limited resource(bandwidth) between a mobile user and a fixed network. So, security features for IMT-2000 are designed to meet the limited capacity. In this paper, we analyze the required security features and mechanism, and design network access security feature effective for IMT-2000 Systems. The design includes security functions allocation to each system. Finally, discuss the computational power of each system based on at]coated functions to it