• 한국정보시스템학회지:정보시스템연구
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• 제5권
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• pp.345-371
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• 1996

Previous studies on user training have largely focused on assessing models which describe the determinants of information technology usage or examined the effects of training on user satisfaction, productivity, performance, and so on. Scant research efforts have been made, however, to examine those effects of training by using theoretical models. This study presented a conceptual models to predict intention to use information technology and conducted an experiment to understand how training for computer skill acquisition affects primary variables of the model. The data were obtained from 32 student subjects of an experimental group and 31 students of a control group, and the information technology employed for this study was a university electronic mail system. The study results revealed that attitude toward usage and perceived behavioral control helped to predict user intentions ;; outcome expectations were positively related to attitude toward usage ; and self-efficacy was positively related to perceived behavioral control. The hands-on training for the experimental group led to increases in perceived ease of use, self-efficacy and perceived behavioral control. The changes in those variables suggest more causal effects of user training than other survey studies.

• 한국산업정보학회:학술대회논문집
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• 한국산업정보학회 1996년도 추계 학술 발표회 발표논문집
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• pp.29-48
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• 1996

Previous studies on user training have largely focused on assessing models which describe the determinants of information technology usage or examined theeffects of training, on user satisfaction, productivity, performance and so on. Scant research efforts have been made, however, to examine those effects of training by using theoretical models. This study presented a conceptural model to predict intention to use information technology and conducted an experimentto understand how training for computer skill acquisition affects primary variables of the model. The data were obtained from 32 student subjects of an experimental group and 31 students of a control group, and the information technology employed for this study was a university's electronic mail system. The study results revealed that attitude toward usage and perceived behavioral control helped to predict user intentions ; outcome expectations were positively related to attitude toward usage ; and self-efficacy was positively related to perceived behavioral control. Thd hands-on training for the experimental group led to increases in perceived ease of use, self-efficacy and perceived behaviroal control. The changes in those variables suggest more causal effects of user training than other survey studies.

• 한국정보과학회논문지:정보통신
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• 제34권5호
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• pp.405-422
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• 2007

최근 네트워크의 발전에 따라 홈 네트워크에도 많은 연구가 진행되고 있다. 현재 홈 네트워크에서는 각 디바이스별로 ACL을 이용하여 접근 제어 정책을 관리하는 방법이 가장 많이 사용되고 있고, EAM(Extranet access management)이 솔루션 형태로 응용되고 있으며, 보안 운영체제에 대한 연구가 공개 운영체제를 바탕으로 진행되고 있다. 또한 흠 서버 중심의 흠 네트워크 사용자 인증 메커니즘 등도 연구되고 있다. 그러나 이러한 연구들은 다음과 같은 문제점이 있다. 첫째, 홈 네트워크에서 사용될 것으로 예상되는 접속기술의 전송범위가 넓어 인증되지 않은 외부 단말기의 접속이 가능하고, 둘째, 사용자가 별도의 필요 정보를 일일이 디바이스에 설정할 필요가 있어 불편하다. 셋째, 사용자 프라이버시나 편의성을 고려하고 있지 않다. 이질적인 다양한 기술들이 존재하는 홈 네트워크 환경에서 OSGi는 상호운용성을 보장하는 서비스 플랫폼을 제공한다. 여기에서 사용자 접근제어는 위와 같은 문제점이 있어서는 안되는 홈 네트워크 보안의 핵심 분야 중에 하나지만 아직 구체적인 연구가 진행되고 있지 않다. 따라서 본 논문에서는 OSGi 서비스 플랫폼이 운영되는 홈 네트워크 환경에서 사용자 접근제어를 위한 RBAC 기반의 권한부여 정책 관리 프레임워크와 접근제어 운영방법을 제안한다. 제시된 접근제어 프레임워크는 OSGi 표준에서 명확하게 언급되지 않았던 부분들을 고려사항으로 나열하고, 이 문제들을 해결하는 방법들을 프레임워크로 제안한다. 제안하는 프레임워크에서는 홈 게이트웨이의 제한된 자원에 대해 RBAC의 개념을 이용하여 사용자 접근제어에 대한 정책변경의 횟수를 줄이는 효율적이고 경제적인 운영 방법을 제시한다. 또한 본 논문에서 제안하는 정책은 사용자역할정책과 권한할당정책을 개별적으로 정의한 후 사용자 정보를 댁내에서 결정함으로써, 사용자 편의성을 높여주고 프라이버시 문제를 해결하도록 방안을 제시한다.

• Journal of Communications and Networks
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• 제18권4호
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• pp.589-599
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• 2016

Most existing resource management problem models arise from the original desire of allocating resources in either a user-centric or network-centric manner. The difference between their objectives is obvious: user-centric methods attempt to optimize the utility of individual users, whereas network-centric models intend to optimize the collective utilities of the entire network. In this paper, from the above two aspects, we analyze the robust power control problem in device-to-device (D2D) communication underlaying cellular networks, where two types of channel uncertainty set (e.g., ellipsoidal and column-wise) are considered. In the user-centric method, we formulate the problem into the form of a Stackelberg game, where the energy efficiency (EE) of each user is the ingredient of utility function. In order to protect the cellular user equipment's (CUE) uplink transmission, we introduce a price based cost function into the objectives of D2D user equipment (DUE). The existence and uniqueness of the game with the influence of channel uncertainty and price are discussed. In the network-centric method, we aim to maximize the collective EE of CUEs and DUEs. We show that by the appropriate mathematical transformation, the network-centric D2D power control problem has the identical local solution to that of a special case of the user-centric problem, where price plays a key role. Numerical results show the performance of the robust power control algorithms in the user-centric and network-centric models.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.748-751
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• 1997

The White Beamline of the Pohang Accelerator Laboratory(PAL) consists of main and second slits, a microprobe system, two ion chambers, a video-microscope, and a Si(Li) detector. These machine components must be controlled remotely through computer system to make user experiments precise and speedy. A real-time computer control system was developed to control and monitor these machine components. A VNIEbus computer with OS-9 real-time operating system was used for low-level data acquisition and control. VME I/O modules were used for step motor control and scaler control. The software has modular structure for maximum performance and easy maintenance. We developed database, I/O driver, and control software. We used PC/Window95 for data logging and operator interface. Visual C++ was used graphical user interface programming. RS232C was used for communication between VME and PC.

• 제어로봇시스템학회논문지
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• 제13권3호
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• pp.242-248
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• 2007

In this paper, we implement the internet-based remote control system for intelligent robot. For remote control of the robot, it uses the socket communication of the TCP/IP. It consists of the user interface and the robot control interface. Robot control interface transmits the navigation and environmental informations of the robot into the user interface. In order to transmit the large environmental images, a JPEG compression algorithm is used. User interface displays the navigation status of the robot and transmits the navigation order into the robot control interface. Also, we propose the design method of the fuzzy controller using navigation data acquired by expert's knowledge or experience. To do this, we use virus-evolutionary genetic algorithm(VEGA). Finally, we have shown the proposed system can be operated through the real world experimentations.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.957-962
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• 2005

Today, the elderly is increasing gradually in the Republic of Korea society and this problem will be more serious in the near future. Therefore, engineering support for aged people is required. We are establishing a new field of healthcare engineering for elderly people and aiming to support for aged people and disabled people using adaptive control and instrument technology. In this paper, the goal is to implement the shared control of a robot mobility aid for the elderly. As using this type of assistive technology to be useful by its intended user community, it supports elderly people and handicapped people to live independently in their private homes. The interface transforms the force applied by the user into the robot's motion. Devices like buttons, joysticks, and levers already exist for relaying user input; however, they require hand displacement that would loosen or otherwise release the user's hold. Such interfaces make operation very difficult and potentially unsafe. Therefore, we propose a shared control system. It's safe more than joysticks and buttons. The shared control is a means of registering the user's intention through physical interaction. It's an important component in the development of robotic elderly assistant. The concept of shared control describes a system which is two or more independent control systems. We are using that the three component blocks consist of pressure sensor (flexible force sensor), circuit of measurement and transfer function. Experimental trials of this paper have been tested at the indoor environment. The robot is able to know the user intended direction through haptic device were logged along with the robot's force sensor.

• International Journal of Internet, Broadcasting and Communication
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• 제12권2호
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• pp.1-7
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• 2020

The secure access the lighting, Heating, ventilation, and air conditioning (HVAC), fire safety, and security control boxes of building facilities is the primary objective of future smart buildings. This paper proposes an authorized user access to the electrical, lighting, fire safety, and security control boxes in the smart building, by using color grid coded optical camera communication (OCC) with face recognition Technologies. The existing CCTV subsystem can be used as the face recognition security subsystem for the proposed approach. At the same time a smart device attached camera can used as an OCC receiver of color grid code for user access authentication data sent by the control boxes to proceed authorization. This proposed approach allows increasing an authorization control reliability and highly secured authentication on accessing building facility infrastructure. The result of color grid code sequence received by the unauthorized person and his face identification allows getting good results in security and gaining effectiveness of accessing building facility infrastructure. The proposed concept uses the encoded user access authentication information through control box monitor and the smart device application which detect and decode the color grid coded informations combinations and then send user through the smart building network to building management system for authentication verification in combination with the facial features that gives a high protection level. The proposed concept is implemented on testbed model and experiment results verified for the secured user authentication in real-time.

• 정보보호학회논문지
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• 제31권3호
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• pp.341-351
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• 2021

최근에 분산ID관리처럼 개인정보를 주체적으로 관리하는 기술이 주목받고 있지만, 기존에 제시된 블록체인 기반의 접근제어 연구들은 사용자에게 충분한 수준의 개인정보 접근제어 방안을 제공하지 못하고 있다. 본 논문은 퍼미션 블록체인 기술과 표준화된 프라이버시 보호 기술을 결합한 방안을 제안한다. 사용자의 접근제어 개입을 위해 프라이버시 제어 표준인 UMA2를 준용하는 토큰 기반의 사용자 접근제어 서비스를 블록체인 분산어플리케이션에 적용하였다. 블록체인과 UMA2를 연동함으로써 기존 블록체인이 제공하지 못했던 사용자 중심의 접근제어 기능을 제공한다. 또한 UMA2의 단점인 엔터티의 프라이버시 문제와 보안성, 가용성 이슈를 해결하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권2호
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• pp.709-730
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• 2017

To address the challenge of unprecedented growth in mobile data traffic, ultra-dense network deployment is a cost efficient solution to offload the traffic over some small cells. The overlapped coverage areas of small cells create more than one candidate access points for one mobile user. Signal strength based user association in IEEE 802.11 results in a significantly unbalanced load distribution among access points. However, the effective bandwidth demand of each user actually differs vastly due to their different preferences for mobile applications. In this paper, we formulate a set of non-linear integer programming models for joint user association control and user demand guarantee problem. In this model, we are trying to maximize the system capacity and guarantee the effective bandwidth demand for each user by soft-association control with a software defined network controller. With the fact of NP-hard complexity of non-linear integer programming solver, we propose a Kernighan Lin Algorithm based graph-partitioning method for a large-scale network. Finally, we evaluated the performance of the proposed algorithm for the edge users with heterogeneous bandwidth demands and mobility scenarios. Simulation results show that the proposed adaptive soft-association control can achieve a better performance than the other two and improves the individual quality of user experience with a little price on system throughput.