• Proceedings of the Korean Operations and Management Science Society Conference
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• 2007.11a
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• pp.464-468
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• 2007

In cognitive radio systems, secondary users, unlicensed users, can use primary users' spectrum to increase spectrum efficiency. At that time, the systems must satisfy primary users' QoS. When secondary users use cognitive radio systems, secondary users communication can be terminated, because of satisfying primary users' QoS. However, secondary users' communication terminating is not good for both secondary users and whole systems. So, cognitive radio systems need an efficient algorithm for secondary users of admission control and keeping connections. In this paper, we present an algorithm which consist of two part, admission control and connections control.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.5 no.11
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• pp.2254-2271
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• 2011

Access control in dynamic environments needs the ability to provide more access opportunities of information to users, while also ensuring protection information from malicious users. Trust and risk are essential factors and can be combined together in access control decision-making to meet the above requirement. In this paper, we propose the combination of the trust and risk in access control to balance information accessibility and protection. Access control decision is made on the basis of trustworthiness of users and risk value of permissions. We use potential relations between users and relations between permissions in access control. Our approach not only provides more access opportunities for trustworthy users in accessing permissions, but also enforces traditional access control constraints such as Chinese Wall policy and Separation of Duty (SoD) of Role-Based Access Control (RBAC) model in an effective way.

• Korean Journal of Community Nutrition
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• v.9 no.1
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• pp.47-57
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• 2004

The study purpose was to investigate the factors related to fast food consumption of university students. Factors were identified using the Theory of Planned Behavior. Based on the pilot study, 18 behavioral beliefs, 7 normative beliefs and 19 control beliefs were identified. Data (n = 269) were analyzed using analysis of variance or $X^2$,/TEX> tests. Subjects were categorized into non-users (27.9%), users (42%) and frequent users ( $\geq$ 2 times/week, 30.1%). Regarding behavioral beliefs, users or frequent users responded more positively on advantages of eating fast foods including ‘taste’ (p < 0.001), ‘making me feel full’(p < 0.001), ‘diverse menus’(p < 0.05) than non-users. Compared to users, non-users responded more positively on the item that eating fast foods leads to eat vegetables less (p < 0.05), and negatively on ‘making me eat more salt’(p < 0.05). Most of the referent groups, parents (p < 0.001), sisters/brothers (p < 0.01), relatives (p < 0.01), friends (p < 0.05), boy/girl friends (p < 0.05) were important sources of influence regarding subjects' fast food consumption. Users or frequent users felt less control over factors or situations that make it consume fast foods (9 out of 19 control beliefs). These factors included; availability issues (p < 0.001), ‘not having other foods on hand’(p < 0.01), ‘others eating together like fast foods’, ‘convenience’, ‘social increase in fast food use’, ‘easy to get fast foods anytime’(p < 0.05). In addition, users of fast foods were more likely to eat fast foods when they don't have time, when they do not like to cook, when they feel hungry (p < 0.05). These results suggest that interventions for university students include strategies to moderate fast food use by modifying behavioral beliefs, suggesting alternative menus and behavior modification techniques, increasing perception of control, and eliciting social support.

• ETRI Journal
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• v.40 no.6
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• pp.813-823
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• 2018

In existing mobile computing environments, users need to choose between their privacy and the services that they can receive from an application. However, existing mobile platforms do not allow users to perform such trade-offs in a fine-grained manner. In this study, we investigate whether users can effectively make utility-privacy trade-offs when they are provided with a multilevel privacy control method that allows them to recognize the different quality of service that they will receive from an application by limiting the disclosure of their private information in multiple levels. We designed a research model to observe users' utility-privacy trade-offs in accordance with the privacy control methods and other factors such as the trustworthiness of an application, quality level of private information, and users' privacy preferences. We conducted a user survey with 516 participants and found that, compared with the existing binary privacy controls, both the service utility and the privacy protection levels were significantly increased when the users used the multilevel privacy control method.

• Journal of Institute of Control, Robotics and Systems
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• v.7 no.3
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• pp.255-262
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• 2001

According to the advancement of web related technologies, many works on robots using these technologies, called web-based robots enables sharing of expensive equipments as well as control of remote robots. But none of the existing methods about web-based robots in-clude robot simulators in their web browser, which transfer appropriate information of a remote place to the local users. In this paper, a web-based robot simulator is proposed and developed to control a remote robot by using the web. The proposed simulator can transfer the 3D information about the remote robot to the local users by using 3D graphics, which has not been previously developed. Also, it sends the camera image of a remote place to the local users so that the users can use this camera image as well as 3D information in order to control the remote robot.

• The Journal of the Korea Contents Association
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• v.5 no.6
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• pp.184-192
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• 2005

The best way to express space effectively on internet is to use 3D VR(Virtual Reality) contents. But it is too difficult to control the 3D VR space with the 2D device. So the content makers cannot solve this problem easily. Besides they define the UI control in their own subjective way which makes the users confused. The purpose of this study is to present the grounds for the Control UI standardization by studying the deriving improvement direction. First of all, we categorize current control UI designs for space-VR on web service by controlling method features into three Types. Next we itemize the main improvement direction that is based on our analysis. First, the UI design that maintains for a typical 2D Input Device method to help the beginner users. Secondly, the concise UI that allows users to Immerse easily in VR. Thirdly, the control level construction that satisfies both users who are skillful at 3D games and users who have little experience with these devices. In this way, we propose the most suitable control UI model that satisfies these improvement directions. We expect the result of our study to serve as an important basis for the standardization of VR services.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.9A
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• pp.1013-1021
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• 2004

In the WCDMA mobile multimedia communication system, the adaptive array antenna IS adopted to improve the performance of the system by reducing inter-user interference using antenna beam control. Usually, the interference resulted from the higher data rate users is much more significant to the lower data rate users than the other way around, so the overall performance can be enhanced by reducing the interference from higher data rate users. In order to maximize the efficiency of adaptive antenna operation, an optimal call admission control, especially during handoff, adaptive to the data rates is a critical problem. In this paper, We propose a call admission control algorithm based on the Soft QoS concept for the efficient processing of the handoff of higher data rate calls, and an adaptive handoff control mechanism according to the data rates. The proposed algorithm has been evaluated by computer simulation that it accommodates high data rate users among many lower data rate users much better, and the average call blocking probability for lower rate users becomes much lower than the conventional call admission control algorithm.

• Asia-Pacific Journal of Business
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• v.13 no.3
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• pp.19-34
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• 2022

Purpose - The purpose of this study is to examine whether a psychological concept enhances healthcare users' service experience. Specifically, the study proposes and empirically examines a model of perceived control in which the user's sense of control is postulated as exerting positive influences upon his/her motivation, self-efficacy associated with his/her role as a patient, and satisfaction with his/her medical service experience. Methodology - Data were collected by a professional research company, using an online survey method. Participants of the study included adults nineteen years or older who had visited a medical service institute at least once during the previous one-year period. For the test of the research hypotheses, structural equation modeling using AMOS was used. Findings - Findings of this study denote a unique insight into the users' comprehension of medical service experiences and their behaviors. First, the concept of perceived control is identified as a factor that enhances the quality of individuals' medical service experiences. A sense of control directly influences medical users' self-efficacy to comply with doctor's recommendations, their motivation to comply with doctor's recommendations, and their satisfaction with the medical service experience. Second, one's perceived self-efficacy is found to exert positive influences upon both motivation and satisfaction. Third, one's motivation to comply with the doctor's recommendation is found to exert a positive influence upon one's satisfaction. Additionally, perceived control is found to exert an indirect influence upon medical service users' satisfaction through the mediation of both self-efficacy and motivation. Research Implications - The findings of the study support the notion that perception of control among medial service users enhances their service experience as patients. The main thrust of this study suggests that it is necessary for healthcare practitioners to consider implementing service encounter strategies that purposefully enhance the sense of control among their patients. The identification of significant inter-relationships among perceived control, motivation, self-efficacy, and satisfaction among medical service customers should also serve as a meaningful seed for further research pursuits.

• Proceedings of the KIEE Conference
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• 2006.07d
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• pp.1913-1914
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• 2006

Modem Industrial control systems tend to adopt a variety of intelligent wireless device controllers to interface front-end computers with active components of the industrial device. Some of the intelligent control systems come equipped with a wireless SMS(Simple Message Service) interface giving an opportunity to use fault alarm Interlock system. Immediately send warning or alert messages to Mobile devices or remote users. Real time monitoring the SMS systems by Mobile devices. Control systems remotely by mobile devices in emergency situation. In order to provide against system fault, SMS Mobile System will enable system administrator to promptly access, monitor and control the system whenever users want and wherever users are, by utilizing wireless Internet and mobile devices. This paper presents the Mobile SMS system for PAL Control System.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39B no.2
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• pp.61-74
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• 2014

In recent years, development of femtocells are receiving considerable attention towards increasing the network coverage, capacity, and improvement in the quality of service for users. In 3GPP LTE-Advanced (LTE-A) system, to efficiently utilize the bandwidth, femtocell and macro cell uses the same frequency band, but this deployment poses a technical challenge of cross-tier interference to macro users. In this paper, the novel quality of service based fractional power control (QoS-FPC) scheme under the heterogeneous networks environment is proposed, which considers the users priority and QoS-requirements during the power allocation. The proposed QoS-FPC scheme has two focal points: firs, it protects the macrocell users uplink communication by limiting the cross-tier interference at eNB below a given threshold, and second, it ensures the optimization of femtocell users power allocation at each power adjustment phase. Performance gain is demonstrated with extensive system-level simulations to show that the proposed QoS-FPC scheme significantly decreases the cross-tier intereference and improves the overall users throughput.