• Journal of the Korean Institute of Intelligent Systems
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• v.17 no.5
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• pp.712-717
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• 2007

Using home network system including home server, home service robot, a variety of device, it is generally known that application of Multi Agent System for performing variously distributed process that can be occur in home environment, is efficient method. In this system, it is intelligent service robot that a key of human interface and physical service offer Therefore, using application of established multi agent system, we can defined Multi Agent Robot System. In 'open' home environment, between all agent data interaction and cooperation are needed for Multi Agent System offer to user that more efficient service. For this, we focus our attention on define as agent that can autonomic drive and offer to user that physical service robots and, design, suggest the simulator can display that between robot agents communication or between other agents, like home server, and robot agents communication information to user interface.

• Journal of Communications and Networks
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• v.13 no.3
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• pp.232-239
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• 2011

This paper investigates the user selection problem of successive zero-forcing precoded multiuser multiple-input multiple-output (MU-MIMO) downlink systems, in which the base station and mobile receivers are equipped with multiple antennas. Assuming full knowledge of the channel state information at the transmitter, dirty paper coding (DPC) is an optimal precoding strategy, but practical implementation is difficult because of its excessive complexity. As a suboptimal DPC solution, successive zero-forcing DPC (SZF-DPC) was recently proposed; it employs partial interference cancellation at the transmitter with dirty paper encoding. Because of a dimensionality constraint, the base station may select a subset of users to serve in order to maximize the total throughput. The exhaustive search algorithm is optimal; however, its computational complexity is prohibitive. In this paper, we develop two low-complexity user scheduling algorithms to maximize the sum rate capacity of MU-MIMO systems with SZF-DPC. Both algorithms add one user at a time. The first algorithm selects the user with the maximum product of the maximum column norm and maximum eigenvalue. The second algorithm selects the user with the maximum product of the minimum column norm and minimum eigenvalue. Simulation results demonstrate that the second algorithm achieves a performance similar to that of a previously proposed capacity-based selection algorithm at a high signal-to-noise (SNR), and the first algorithm achieves performance very similar to that of a capacity-based algorithm at a low SNR, but both do so with much lower complexity.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.11
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• pp.2607-2612
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• 2014

In this paper, we propose a distributed user scheduling with transmit power control based on the amount of interference inflicted to other BSs in multi-cell uplink networks. Assuming that the channel reciprocity time-division duplexing(TDD) system is used, the channel state information (CSI) can be obtained at each user from pilot signals from other BSs. The amount of generating interference to other BSs will be calculated at each user. Especially, in this paper, we propose the threshold-based transmit power control, in which a user decrease its transmit power if its generating interference to other BSs is larger than a predetermined threshold. Simulation results show that the proposed technique significantly outperforms the existing user scheduling algorithms.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.2
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• pp.167-173
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• 2015

Extraction of Finger-end points is one of the most process for user multi-commands in the Hand-Gesture interface technology. However, most of previous works use the geometric and morphological method for extracting a finger-end points. Therefore, this paper proposes the method of user finger-end points extraction that is motivated a ultrared diffused illumination, which is used for the user commands in the multi-touch display device. Proposed air-mouse is worked by the quantity state and moving direction of extracted finger-end points. Also, our system includes a basic mouse event, as well as the continuous command function for expending a user multi-gesture. In order to evaluate the performance of the our proposed method, after applying to the web browser application as a command device. As a result, the proposed method showed the average 90% success-rate for the various user-commands.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.10
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• pp.1379-1385
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• 2018

In the conventional multi-user superposition transmission, the power allocation coefficients of data symbols and the received signal processing of users are determined by the condition of instantaneous channel powers. However, the use of instantaneous channel powers can increase the system complexity. Hence, we consider fixed multi-user superposition transmission using average channel powers. The fixed multi-user superposition transmission can reduce the system complexity because it uses the condition of average channel powers that slowly change over time in order to decide the power allocation coefficients and the received signal processing. In this paper, we analyze the average symbol error rate for the fixed multi-user superposition transmission. In particular, an expression for the average symbol error rate of M-ary Quadrature Amplitude Modulation is derived assuming Rayleigh fading channels. In addition, through the numerical results, we show that the conventional and fixed multi-user superposition transmissions achieve the similar average symbol error rate performances at the user in the severe channel condition.

• KIPS Transactions on Computer and Communication Systems
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• v.4 no.3
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• pp.91-96
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• 2015

Recently, the 'mobility' is one of the essential item in the field of IT. This means that 'mobility' are good mediators to get collecting user's behavior and provide freedom of mobility service for user's. This paper is proposed a mobility process orchestration(MPO) model that provide multimedia to various devices. The orchestration model provides the structure and function that can be objectify a physical devices in a user's environment to provide orchestrated service of various devices to user using a concept of MSMP(Multi Source Multi Platform). Also, using the concept of Choreography can be extracted appropriate device of the various media formats for harmonious service.

• Journal of the Korean Institute of Educational Facilities
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• v.17 no.2
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• pp.3-12
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• 2010

The purpose of this study was to provide the planning guideline for the multi-purposed classroom in the elementary school and middle school using questionnaire and user participation method. As the user participation method, the design workshop in the study contains participation techniques, community action planning, and participation game. The design workshop used the design kit as a communication tool. Four user groups, selected from teachers and child in the elementary school and middle school, to be reconstructed, participated in a design workshop with design kit, and each group produced their own plans. The result of this study is as follows; (1) Teachers wanted multi-purposed classroom to be used by two classes. (2) The size of the multi-purposed classroom was preferred 1.5 times(30 py.) of the regular classroom. (3) By considering the characteristics of students it was required the open space in elementary, but required it to be separated from the regular classroom in middle school. (4) Through the analysis, we could grasp the processes that the users' needs were practically applied to design. Our design workshop method should be hereafter modified and advanced, but showed the usefulness in many aspects.

• Journal of the Korea Computer Graphics Society
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• v.24 no.3
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• pp.11-20
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• 2018

This study proposes collaboration based multi-user interaction to provide improved presence and satisfying experience to multiple HMD users in immersive virtual reality. The core of the proposed multi-user interaction is to present the direction in which HMD users in virtual reality environment can interact through communication and collaboration with each other based on their separate roles and behaviors. Each user in the virtual collaborative environment uses a hand to interact with a virtual environment or virtual objects. Based on the basic structure, this study designs methods (synchronization and communication) that can be achieved a common goal together through communication and collaboration. Then, this study creates a virtual reality application of arcade genre that considers communication and collaboration in order to verify whether the proposed multi-user interaction provides improved presence and satisfaction experience. And, the survey experiments are conducted for participants. Through these processes, it is confirmed that the interaction in the proposed immersive virtual collaborative environments provide the presence and experience that is satisfactory to all users.

• Journal of Korea Multimedia Society
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• v.8 no.6
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• pp.814-826
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• 2005

The user-centric broadcasting environment includes the agent system and personalized broadcasting services for user-adaptive TV watching. In this paper, we propose broadcasting environment consisting of personalized broadcasting services and a multi-agent broadcasting system for the services. The proposed system employs the intelligent agent technology of the Foundation for Intelligent Physical Agents (FIPA) as well as metadata technology of MPEG-7 and TV-Anytime Forum (TVAF). To verify the usefulness of the proposed environment, we implemented a test-bed and demonstrated the proposed agent system with three services including intelligent user-information management service, information mobility service, and content retrieval service.

• Journal of Digital Convergence
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• v.12 no.2
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• pp.321-326
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• 2014

The needs for IT accessibility for disabled persons has increased for recent years. So, it is very important to support multi-modal interfaces, such as voice and vision recognition, TTS, etc. for disabled persons. In this paper, we deal with IT accessibility issues of home networks and show our implemented home network control system model with multi-modal interfaces including voice recognition and animated user interfaces.