• 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.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.3 no.6
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• pp.575-596
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• 2009

Facing limited network resources such as bandwidth and processing capability, the Internet will have congestion from time to time. In this paper, we propose a scheme to maximize the total utility offered by the network to the end user during congested times. We believe the only way to achieve our goal is to make the scheme application-aware, that is, to take advantage of the characteristics of the application. To make our scheme scalable, it is designed to be class-based. Traffic from applications with similar characteristics is classified into the same class. We adopted the RED queue management mechanism to adaptively control the traffic belonging to the same class. To achieve the optimal utility, the traffic belonging to different classes should be controlled differently. By adjusting link bandwidth assignments of different classes, the scheme can achieve the goal and adapt to the changes of dynamical incoming traffic. We use the control theoretical approach to analyze our scheme. In this paper, we focus on optimizing the control on two types of traffic flows: TCP and Simple UDP (SUDP, modeling audio or video applications based on UDP). We derive the differential equations to model the dynamics of SUDP traffic flows and drive stability conditions for the system with both SUDP and TCP traffic flows. In our study, we also find analytical results on the TCP traffic stable point are not accurate, so we derived new formulas on the TCP traffic stable point. We verified the proposed scheme with extensive NS2 simulations.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.10
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• pp.2708-2730
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• 2012

The growing concern for the protection of personal information has made it critical to implement effective technologies for privacy and data management. By observing the limitations of existing approaches, we found that there is an urgent need for a flexible, privacy-aware system that is able to meet the privacy preservation needs at both the role levels and the personal levels. We proposed a conceptual system that considered these two requirements: a graph-based, access control model to safeguard patient privacy. We present a case study of the healthcare field in this paper. While our model was tested in the field of healthcare, it is generic and can be adapted to use in other fields. The proof-of-concept demos were also provided with the aim of valuating the efficacy of our system. In the end, based on the hospital scenarios, we present the experimental results to demonstrate the performance of our system, and we also compared those results to existing privacy-aware systems. As a result, we ensured a high quality of medical care service by preserving patient privacy.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.2
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• pp.1070-1088
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• 2017

Recently, the applications of Internet of Things (IoTs) are growing rapidly. Wireless Sensor Network (WSN) becomes an emerging technology to provide the low power wireless connectivity for IoTs. The IPv6 over low-power wireless personal area networks (6LoWPAN) has been proposed by IETF, which gives each WSN device an IPv6 address to connect with the Internet. The transmission congestion in IoTs could be a problem when a large numbers of sensors are deployed in the field. Therefore, it is important to consider whether the WSN devices have be completely integrated into the Internet with proper quality of service (QoS) requirements. The Software Defined Network (SDN) is a new architecture of network decoupling the data and control planes, and using the logical centralized control to manage the forwarding issues in large-scale networks. In this research, the SDN-based 6LoWPAN Border Router (6LBR) is proposed to integrate the transmission from WSNs to Internet. The proposed SDN-based 6LBR communicating between WSNs and the Internet will bring forward the requirements of end-to-end QoS with bandwidth guarantee. Based on our experimental results, we have observed that the selected 6LoWPAN traffic flows achieve lower packet loss rate in the Internet. Therefore, the 6LoWPAN traffic flows classified by SDN-based 6LBR can be reserved for the required bandwidth in the Internet to meet the QoS requirements.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.504-506
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• 1997

CCD camera is usually used for monitoring device. In most cases, he monitoring is performed from long distance. In this study, a camera system controlled through internet is developed. Using the system, not only we can get image information in real time but also we can control the orientation of the camera from long distance. Furthermore wireless communication is carried out between the camera and the server computer for verity of the application.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1460-1464
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• 2003

This paper describes the design and implementation techniques of a generic Internet based telerobotic system. The purpose is to make precious technical information and hands-on experience of the authors widely available for the research community. The paper is based on the telerobotics system that the authors recently implemented between KAIST and Saga University, Japan. In its current functionality, two control modes can be exercised; high-level supervisory control, and low-level supervisory control.

• International Journal of Internet, Broadcasting and Communication
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• v.8 no.1
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• pp.1-6
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• 2016

Keeping a system in stable state is one of the important issues of control theory. The main goal of our basic research is stability of unmanned aerial vehicle (quadrotor). This type of system uses a variety of sensors to stabilize. In control theory and automatic control system to stabilize any system it is need to apply feedback control based on information from sensors. Our aim is to provide balance based on the 3D spatial information in real time. We used PID control method for stabilization of a seesaw balancing system and the article presents our experimental results. This paper presents the possibility of balancing of seesaw system based on feedback information from stereo vision system only.

• Journal of the Korea Society of Computer and Information
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• v.19 no.3
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• pp.127-134
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• 2014

This study is to suggest ideas for policies and theories by analysing the control effectiveness of parents' raising attitude on the influence of adolescents' self-control and Internet Expectation. For this, the questionnaire surveys composed of measures on adolescents' self-control, Internet Expectation, and parents' raising attitude, were carried out to 312 high school students in G metropolitan city, and the relation of the variables were studied. As a result of research, it was found out adolescents' self-control and Internet Expectation influenced the internet addiction. Expecially, the influence of adolescents' self-control and Internet Expectation of internet addiction was differed by the parent's raising attitude. In this research, the ideas of policies were suggested based on the analysis of the results.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.1
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• pp.34-39
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• 2007

According to the active use of internet the need for security in various environment is being emphasized. Moreover with the broad use of Messenger on PC and P2P applications. the security and management of individual hosts on internet became very important issues. Therefore in this paper we propose the design and implementation of a host based access control system for the hosts on internet including window based PC which provides access control, information on packets, and record and monitoring of log files.

• Journal of Institute of Control, Robotics and Systems
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• v.9 no.8
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• pp.585-591
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• 2003

A virtual force is generated and fed back to the operator to make the teleoperation more reliable, which reflects the relationship between a slave robot and an uncertain remote environment as a form of an impedance. In general, for the teleoperation, the teleoperated mobile robot takes pictures of the remote environment and sends the visual information back to the operator over the Internet. Because of the limitations of communication bandwidth and narrow view-angles of camera, it is not possible to watch certain regions, for examples, the shadow and curved areas. To overcome this problem, a virtual force is generated according to both the distance between the obstacle and the robot and the approaching velocity of the obstacle w.r.t the collision vector based on the ultrasonic sensor data. This virtual force is transferred back to the master (two degrees of freedom joystick) over the Internet to enable a human operator to estimate the position of obstacle at the remote site. By holding this master, in spite of limited visual information, the operator can feel the spatial sense against the remote environment. It is demonstrated by experiments that this collision vector based haptic reflection improves the performance of teleoperated mobile robot significantly.