• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2003년도 가을 학술발표논문집 Vol.30 No.2 (2)
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• pp.253-255
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• 2003

We address an integrated multimedia framework based on a software agent platform for context-aware multimedia computing. We adopt the FIPA (Foundation for Intelligent Physical Agents) platform which provides agent communications and management mechanisms. In order to express context information, we use MPEG-21 metadata for describing user characteristics and usage environment. We encapsulate such context information as a FIPA message to be delivered between agents. Based on context information, appropriate multimedia content delivery becomes possible. We present our system implementation with a use case scenario and show that our proposed framework is effective for context-aware multimedia computing so that personalization of multimedia consumption can be possible.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제14권2호
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• pp.514-537
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• 2020

Wireless sensor network (WSN) is a distributed network composed of many sensory nodes. It is precisely due to the clustering unevenness and cluster head election randomness that the energy consumption of WSN is excessive. Therefore, a many-objective optimization WSN energy balance model is proposed for the first time in the clustering stage of LEACH protocol. The four objective is considered that the cluster distance, the sink node distance, the overall energy consumption of the network and the network energy consumption balance to select the cluster head, which to better balance the energy consumption of the WSN network and extend the network lifetime. A many-objective optimization algorithm to optimize the model (LEACH-ABF) is designed, which combines adaptive balanced function strategy with penalty-based boundary selection intersection strategy to optimize the clustering method of LEACH. The experimental results show that LEACH-ABF can balance network energy consumption effectively and extend the network lifetime when compared with other algorithms.

• ETRI Journal
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• 제38권5호
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• pp.799-806
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• 2016

In this paper, we propose an emergency wake-up alert system (EWAS) for providing accurate and rapid emergency information. The proposed system can provide an emergency wake-up alert service without an additional frequency allotment by utilizing the guard band of the Advanced Television Systems Committee (ATSC) Terrestrial Digital Television (DTV) system. The design target of the proposed system is to match the indoor reception coverage of EWAS with the outdoor reception coverage of the ATSC DTV system. To achieve this, the proposed system should be about 35.65 dB more robust than the ATSC DTV system. The simulation results show that the proposed system offers an emergency wake-up alert service supporting a data rate of up to 23 bps.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 B
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• pp.1257-1259
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• 1996

In this paper, we introduce an integrated communication and control system(ICCS) for control of a crane. The system is integrated with a compasite technique as a network interfacing, a user interfacing and a system control for continuous process like as a container crane. The field-bus(Profibus) network module is used to interconnect each input/output module with main control unit. The MMI system for user interfacing is integrated with an ODBC-based data management tool and IECl131-based control logic design tool(Soft-Logic Designer:SLD). The each programmed control task in the main Controller is executed using a petri-net based scheduler.

• 공학교육연구
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• 제5권1호
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• pp.27-33
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• 2002

최근에 멀티미디어 기술과 결합된 공학교육용 가상 웹사이트가 다양한 형태로 출현함에 따라 공학교육의 인터넷 응용에 많은 관심이 모아졌다. 그러나 단방향성 통신, 단순한 텍스트나 이미지 기반의 웹 문서 그리고 동기부여가 없는 지루한 교육진행과정 등은 가상공간에서의 교육의 효율성을 저하시켜왔다. 따라서 본 논문에서는 학습과정에 있어서 효율성을 극대화하기 위한 가상실험시스템을 제안한다. 제안된 디지털 논리회로 가상실험시스템의 웹의 멀티미디어 능력을 증대시킬 수 있는 상호작용적인 학습 환경을 제공한다. 제안된 가상실험실은 실제 대학에서의 실험실 환경과 유사하게 구현하였기 때문에 학습자들은 가상실험실을 통해 유사한 실험결과를 얻을 수 있다. 제안된 가상실험실은 원리이해 학습실, 모의실험 학습실, 가상실험 학습실 그리고 관리시스템의 4가지로 구성되어 있다. 이러한 혁신적인 교수-학습환경하에서 학습효율은 물론 교수의 생산성을 크게 향상시킬 수 있을 것으로 생각된다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권9호
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• pp.3016-3033
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• 2014

The downlink performance of distributed antenna systems (DAS) with antennas selection is investigated in Rayleigh fading multicell environment, and the corresponding system capacity and bit error rate (BER) analysis are presented. Based on the moment generating function, the probability density function (PDF) and cumulative distribution function (CDF) of the effective signal to interference plus noise ratio (SINR) of the system are first derived, respectively. Then, with the available CDF and PDF, the accurate closed-form expressions of average channel capacity and average BER are further derived for exact performance evaluation. To simplify the expression, a simple closed-form approximate expression of average channel capacity is obtained by means of Taylor series expansion, with the performance results close to the accurate expression. Besides, the system outage capacity is analyzed, and an accurate closed-form expression of outage capacity probability is derived. These theoretical expressions can provide good performance evaluation for DAS downlink. It can be shown by simulation that the theoretical analysis and simulation are consistent, and DAS with antenna selection outperforms that with conventional blanket transmission. Moreover, the system performance can be effectively improved as the number of receive antennas increases.

• 한국통신학회:학술대회논문집
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• 한국통신학회 2004년도 추계종합학술대회 논문 초록집
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• pp.351-351
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• 2004

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권11호
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• pp.5360-5376
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• 2017

In this paper, we study the cross-layer design for the AMC/HARQ-based wireless networks, and propose a new dynamic transmission-mode selection scheme to improve system spectrum efficiency. In the proposed scheme, dynamic thresholds for transmission-mode selection in each packet transmission and retransmission are jointly designed under the constraint of the overall packet error rate. Comparing with the existing schemes, the proposed scheme is inclined to apply higher modulation order at the first several (re)transmissions, which corresponds to higher-rate transmission modes thus higher average system spectrum efficiency. We also extend the cross-layer design to MIMO (Multi-input Multi-output) communication scenarios. Numerical results show that the proposed new dynamic transmission-mode selection scheme generally achieves higher average spectrum efficiency than the conventional and existing cross-layer design.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2007년도 Proceedings of ISRS 2007
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• pp.146-148
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• 2007

CMDPS (COMS Meteorological Data Processing System) is the operational meteorological products extraction system for data observed from COMS (Communication, Ocean and Meteorological Satellite) meteorological imager. CMDPS baseline products consist of 16 parameters including cloud information, water vapor products, surface information, environmental products and atmospheric motion vector. Additionally, CMDPS includes the function of calibration monitoring, and validation mechanism of the baseline products. The main objective of CMDPS validation module development is near-real time monitoring for the accuracy and reliability of the whole CMDPS products. Also, its long time validation statistics are used for upgrade of CMDPS such as algorithm parameter tuning and retrieval algorithm modification. This paper introduces the preliminary design on CMDPS validation module.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권7호
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• pp.3100-3116
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• 2016

With the rapid development of urban traffic system and fast increasing of vehicle numbers, the traditional centralized ways to generate the source-destination shortest path in terms of travel time(the optimal path) encounter several problems, such as high server pressure, low query efficiency, roads state without in-time updating. With the widespread use of smart cameras in the urban traffic and surveillance system, this paper maps the optimal path finding problem in the dynamic road network to the shortest routing problem in the smart camera networks. The proposed distributed optimal path generation algorithm employs the delay routing and caching mechanism. Real-time route update is also presented to adapt to the dynamic road network. The test result shows that this algorithm has advantages in both query time and query packet numbers.