• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.133-134
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• 2006

In this paper the platform system for IEEE 802.15.4 Low Rate WPAN is designed and fabricated. IEEE 802.15.4 Low Rate WPAN system serves the functions and realization of home-area network. According to the IEEE 802.15.4 standard, there are two modes, One is BPSK modulation in 868/915MHz frequency band. The other is O-QPSK modulation in 2.45GHz frequency band. In this paper we implemented the platform system mounted in one PCB board in 868/915MHz frequency band of IEEE 802.15.4 Low Rate WPAN system. We measured that the platform system which consists of digital part and RF part has good performance. Also RF part is realized by design and fabrication of the RF transceiver IC. The key issue is to make the platform system which provides the function of Low Rate WPAN system to meet the requirement of IEEE 802.15.4 standards.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2004.11a
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• pp.477-477
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• 2004

• 한국정보통신설비학회:학술대회논문집
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• 2005.08a
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• pp.222-225
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• 2005

• 한국정보통신설비학회:학술대회논문집
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• 2004.05a
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• pp.131-156
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• 2004

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.2
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• pp.136-143
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• 2013

In this paper, a monitoring system for telecommunication tower using wireless sensor network is presented. Although safety inspection could be judged by eyesight and calculating original design from now, not only this system can protect perils, estimating data exactly, but also it is effective to management. It is also economic because the system costs cheaper expenses for telecommunication tower of setting it once than for the tower of inspecting its safety regularly. This paper proves that the structure can be managed scientifically and efficiently, and the system contributes not only stabilized telecommunication services for users but reducing damages.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.8
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• pp.1779-1782
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• 2009

The developed system is captured by RS-232 telecommunication receiving data (temperature and humidity of each incubator) through radio frequency sensor network system and is made by monitoring system for one person collecting each channel data. This monitoring system is capable of monitoring not only PDA through TCP/IP telecommunication but also personal computer. This system is actively application on telecommunication function of LabVIEW and PDA module and is considerably saved in processing time than using in other tools.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2006.07a
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• pp.330-330
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• 2006

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2004.11a
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• pp.79-79
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• 2004

• Journal of the Korean Statistical Society
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• v.30 no.4
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• pp.661-666
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• 2001

In this paper we consider an M/G/1 queue where the server of the system has a vacation time and the service policy is limited-1. In this system, upon termination of a vacation the server returns to the queue and serves at most one message in the queue before taking another vacation. We consider two models. In the first, if the sever finds the queue empty at the end of a cacation, then the sever immediately takes another vacation. In the second model, if no message have arrived during a vacation, the sever waits for the first arrival to serve. The analysis of this system is particularly useful for a priority class polling system. We derive Laplace-Stieltjes transforms of the waiting time for both models, and compare their mean waiting times.

• Journal of information and communication convergence engineering
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• v.19 no.2
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• pp.120-129
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• 2021

In this study, the effect of a telecommunication company's safety management system on workers' safety awareness and safety behavior was empirically verified. The main findings are as follows: First, among the factors of the telecommunication company's safety management system, the management supervisor's capability and level of industrial accident investigations were found to have a significant positive effect on workers' safety awareness. Second, workers' safety awareness was observed to exert a significant positive effect on their safety behavior. Third, among the factors of the telecommunication company's safety management system, the management supervisor's capability and industrial accident investigations were found to have a significant positive effect on the safety behavior of workers. Fourth, although the telecommunications safety management system factors, such as management supervisors' capability and industrial accident investigations, were found to have a positive effect on workers' safety awareness, they had no mediated effect on workers' safety behavior through safety awareness.