• Proceedings of the KIEE Conference
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• 2006.10c
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• pp.524-526
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• 2006

We proposes integrated information system, Service Robot Information System(SRIS), for mobile robot. The system has objectives that can heir efficient management and sharing as support information for mobile service robot like recognition, navigation, manipulation and modeling. This paper introduces the concert and architecture of SRIS. An Implementation is done by using ER based database and CAD modeling which is DXF format. The experimental shows the result of object and environment map matching by SLAM. This system is expected that can help reduce the cost and efforts of information management under multiple mobile robot environment.

• Journal of the Korean Operations Research and Management Science Society
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• v.28 no.2
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• pp.139-155
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• 2003

The aim of this study is to identify the data traffic capacity of 3G mobile communication networks, especially of cdma2000-1X networks. Three-layered ON/OFF traffic model is used to describe the dynamics of data traffics and the process of data transmission such as packet scheduling. We construct a simulator fully incorporating packet handling process of cdma2000-lX data network as well as three-layered ON/OFF traffic model describing the behavior of source data traffics. To get influence of traffic parameters on performance measures, the extensive simulations were performed for several data sets which are obtained from real trace data or previous studies. The experimental results show that the engineered throughput satisfying QoS criteria is approximately 25% of total capacity. Finally, some proposals to improve the system capacity are followed.

• The Journal of Korea Robotics Society
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• v.3 no.3
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• pp.194-202
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• 2008

This paper describes a new method for indoor environment mapping and localization with stereo camera. For environmental modeling, we directly use the depth and color information in image pixels as visual features. Furthermore, only the depth and color information at horizontal centerline in image is used, where optical axis passes through. The usefulness of this method is that we can easily build a measure between modeling and sensing data only on the horizontal centerline. That is because vertical working volume between model and sensing data can be changed according to robot motion. Therefore, we can build a map about indoor environment as compact and efficient representation. Also, based on such nodes and sensing data, we suggest a method for estimating mobile robot positioning with random sampling stochastic algorithm. With basic real experiments, we show that the proposed method can be an effective visual navigation algorithm.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.34S no.12
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• pp.19-29
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• 1997

This paper presents stable kinematic modeling and path planning and path tracking algorithms for the poisition control of 4-wheeled 2-d.o.f(degree of freedom) mobile robot. We drived the actuated inverse and sensed forward solution for the calculation of actuator velocity and robot velocities. the deal-reckoning algorithm is introduced to calculate the position of WMR in real time. The gaussian functions are applied to control and to design the smooth orientation angle of WMR and the path planning algorithm for obstacle avoidance is prosed. We composed feedback control system to compensate for error because of uncertainty kinematic modeling and measurement noise. The simulation resutls show that the proposed kinematkc modeling and path planning and feedback control algorithms are useful.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.05a
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• pp.883-889
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• 2005

Micro robots have been developed for many applications: medical, industrial, military, and so on. A small mobile robot was built and it has three legs made of bimorph piezoelectric actuators. It proceeds by vibrating the rear leg and it rotates by vibrating one of the front legs. The locomotion of the robot is described by relative position of mass center and the friction between the legs and the floor. This paper describes the principles of locomotion and modeling of the robot Modeling was simulated to investigate the dynamics of its mobility. The simulation results verified the modeling by showing similar movement of the robot as measured. It remained, however, several problems through experiments such as crooked direction of forward movement and proceeding speed.

• Journal of Information Technology Applications and Management
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• v.27 no.5
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• pp.49-68
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• 2020

The Push-Pull-Mooring (PPM) model employ to explore the factors that affect the switching intention of mobile game players by analyzing the online survey data of 240 mobile game players in China. From the perspective of PPM model, Dissatisfaction with the current mobile game can promote players to leave the current mobile game, and other more attractive mobile games can pull players out of the current mobile game. As a mooring factor, habit can affect players' switching decisions. Players who have formed strong habits in current mobile games are more likely to resist or ignore the attractiveness of other mobile games and stay in the current mobile games rather than migrate to other mobile games. Another result shows that the more dissatisfied with the current mobile game, the higher the quality of alternative (relative challenge) mobile game, and the lower the investment size in the current mobile game, the more reluctant the players are to continue to maintain the relationship with the current mobile game. The higher the player's commitment to the current mobile game, the more likely it is to maintain the relationship with the current mobile game. The empirical results show that the framework of this study is highly consistent with the results of PPM model, and confirming that they can well apply to mobile game situations.

• Journal of Digital Convergence
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• v.13 no.8
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• pp.267-279
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• 2015

The study aimed to examine the longitudinal relationship between addictive use of mobile phones and learning activities for elementary school students and to analyze (1)temporal changes of the addictive use of mobile phones and learning activities, (2)temporal relationship between them, and (3)multiple and complex group analysis across gender on the relationship. For the study, 3-year longitudinal data(2010-2012) of the Korean Children and Youth Panel Survey and autoregressive cross-lagged modeling were used. The findings showed that the addictive use of mobile phones and learning activities had a significant positive effect on the future selves of children over time. The addictive use of mobile phones influenced positively subsequent learning activities, but, the learning activities did not affect the addictive use of mobile phones. Further, there were no significant gender differences in the longitudinal relationship. The study provided the useful data to make guidelines on how to protect mobile phone addiction for elementary school students.

• Journal of Institute of Control, Robotics and Systems
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• v.7 no.9
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• pp.766-773
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• 2001

Omni-directional mobile robots have been popularly employed in several application areas. However, the kinematics for these systems have not been clearly identified, specially for redundantly actuated case which is common in omni-directional mobile robot such as the Nomadic model. For such mobile robot systems, exploitation of redundant actuation as well as singularity analysis has not been extensively addressed. In light of this fact, this paper introduces two different kinematic approaches for omni-directional mobile robots. Then, a singular-free load distribution scheme for redundantly actuated three-wheeled omni-directional mobile robot is proposed. Through simulation, several advantages of redundantly actuated mobile robot in aspect of singularity avoidance, minimization of torque norm, and exploiting several subtasks are presented.

• Journal of Distribution Science
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• v.18 no.11
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• pp.69-77
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• 2020

Purpose: This research aims to verify the role of mobile shopping attributes, trustworthiness, and cultural dimensions on mobile shopping intentions in Saudi Arabia. The originality of the model stems from the verification of the moderating impact of cultural variables, namely collectivism and masculinity, and from the integration of trustworthiness as a variable depending on mobile shopping attributes. Research design, data and methodology: A survey was distributed to 233 consumers with different nationalities living in the Kingdom of Saudi Arabia. Structural equation modeling and multi-group analysis were carried out to verify the conceptual model and the moderating variables. Results: The findings support the influence of several innovation attributes, namely complexity and trialability on behavioral intentions, while relative advantage has a direct impact on trustworthiness. A few paths are moderated by masculinity and collectivism. Conclusions: Culture and mobile commerce attributes need to be thought out by managers as factors influencing mobile commerce segmentation for expatriates and locals. Trustworthiness is also a key factor of mobile shopping adoption. Limitations and future research ideas are presented to enrich the proposed model and improve its predictive validity.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2003.09a
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• pp.587-590
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• 2003

In this paper, the control of the differential drive wheeled mobile robot (DDWMR) is studied. Because the DDWMR have non-holonomic constraints, it cannot be stabilized by smooth feedback. The T-S fuzzy model for the DDWMR is presented and a control algorithm Is developed by well known PID control and LMI based regional pole-placement.