• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.9A
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• pp.712-718
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• 2009

This paper proposes the optimal transmission parameter selection method for an energy efficient Wireless Personal Area Network (WPAN) system which is applicable to the Maritime Telematics targeting for various ship models. Since the transmission parameter selection is an important factor for WPAN system to decide its energy efficiency, we propose an energy consumption model for ship area network (SAN) employing IEEE 802.15.3 based TDMA HR-WPAN model and analyzes the effect of transmission parameter selection on the performance of energy consumption. In particular, the main performance decision parameter of the SAN applying HR-WPAN is path loss, since it is very varied according to the material of shipbuilding such as steel (large ship), FRP (medium size ship) and compound wood (small ship). Thus, we analyzed and demonstrated that the proper transmission parameter selection among transmit power, PHY data rate and fragment size for each ship model guarantee the energy efficiency.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.10A
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• pp.760-768
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• 2009

In this paper, we propose the energy efficient transmission parameter selection method for Wireless Personal Area Network (WPAN) system which is applied to e-Navigation system considering various ship models environment. An appropriate selection of transmission parameters of HR-WPAN system is very essential to be considered for saving WPAN devices' energy consumption, when HR-WPAN system is applied to ship area network (SAN). Therefore, we propose an energy consumption model for a ship area network employing IEEE 802.15.3 based CSMA/CA HR-WPAN model and analyze the effect of transmission parameter selection on the performance of energy consumption. In particular, the path loss is the major performance decision parameter for the SAN employing HR-WPAN system, since it varies according to the material of shipbuilding such as steel(for large ship), FRP(for medium size ship) and compound wood(for small ship). Thus, we analyze and demonstrate that the proper transmission parameter selection of transmit power, PHY data rate and fragment size for each ship model could guarantee energy efficiency.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.10A
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• pp.769-775
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• 2009

This paper proposes the optimal transmission parameter selection method for an energy efficient Wireless Personal Area Network (WPAN) system which is applicable to the Maritime Telematics targeting for various ship models. Since the transmission parameter selection is an important factor for WPAN system to decide its energy efficiency, we propose an energy consumption model for ship area network (SAN) employing IEEE 802.15.3 based TDMA HR-WPAN model and analyzes the effect of transmission parameter selection on the performance of energy consumption. In particular, the main performance decision parameter of the SAN applying HR-WPAN is path loss, since it is very varied according to the material of shipbuilding such as steel (large ship), FRP (medium size ship) and compound wood (small ship). Thus, we analyzed and demonstrated that the proper transmission parameter selection among transmit power, PHY data rate and fragment size for each ship model guarantee the energy efficiency.

• Journal of IKEEE
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• v.13 no.3
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• pp.80-86
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• 2009

TETRA is the standard of Digital Trunked Radio System developed by the ETSI(European Telecommunications Standards Institute). It is adopted as Electric Power IT Wireless Backbone Network in Korea. To use TETRA wireless network, TETRA modem is very necessary. In this paper, the performance measurements of modem and its results are analyzed according to traffics in TETRA network. In this paper, SDS type-4 transmission method is used in the transmission standards suggested by PEI(Peripheral Equipment Interface) of ETSI. Performance measurements are done by varying the data size and transmission interval. The data size is increased by 10 bytes from 10-byte to 140-byte, and it is measured 1,000 times for each transmission interval of 0.5, 1.0, and 1.5 seconds. MU-1000MD of Unimo is used for TETRA modem, and SwMI(Switching and Management Infrastructure) of Teltronic is used for switching system in this paper.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.10a
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• pp.535-538
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• 2010

In this paper, this study goal is development for WSN-based fire prevention systems of using temperature/humidity Sensor. So, distributed sensor nodes structural and packet transfer characteristics study for fire monitoring. Battery-operated wireless sensor networks is data transfer manner of multi-hop. WSN fire prevention system need to sensor nodes management and energy consumption of efficient adjust for sustained action. Thus, study with efficient energy consumption the normal WSN environment is not, characteristics for WSN fire prevention environment.

• Annual Conference of KIPS
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• 2005.05a
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• pp.1641-1644
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• 2005

현재의 인터넷과 같은 전자 통신망과 멀티미디어 시스템의 발달은 고속의 대용량 데이터 전송을 필요로 한다. 초고속 통신 시스템에서의 고속 데이터 전송은 주로 광섬유를 사용하는 광통신으로 이루어지고 있다. FTTH(Fiber To The Home)와 같은 광통신 시스템은 멀티미디어 커뮤니케이션을 위해 필요한 큰 데이터 전송률을 제공할 수 있기 때문에 더욱 더 중요성이 높아지고 있으며 이러한 광통신 시스템에서는 통신환경의 영향을 적게 받고 외부 조절이나 부품이 필요하지 않는 수신기 IC 의 개발이 요구되고 있다. 일반적으로 광통신 수신기에는 고속 동작에 적합한 특성을 가진 GaAs-MESFET 가 사용되고 있으나, 본 논문에서는 0.35um CMOS 2-poly 4-metal 공정을 이용하여 5Gbps 광수신기를 설계하였다. 설계된 수신기는 Preamplifier, Main amplifier, ABC 회로로 구성되어 있다. Transimpedance amplifier 형태의 Preamplifier 는 광검출기에 의해 생성된 전류 신호를 전압 신호로 변환한다. ABC 회로는 Peak_Hold 회로와 Bottom_Hold 회로로 구성되어 있다. 기존의 Peak_Hold 회로에서는 다이오드와 hold capacitor 를 이용하여 peak 값을 검출하도록 되어 있는데, 다이오드를 이용하는 경우 작은 입력 신호전압의 Peak 값을 검출하는 데 한계가 있다. 이러한 단점을 보완하고자 전류 거울형태의 Peak_Hold 회로를 설계하였다. 전류거울(current mirror)형태의 출력 신호의 duty error 를 줄이고 비트 에러율(Bit Error Rate)을 개선하는데 효과적이었다. 설계된 광수신기는 30dB 의 입력 dynamic range 와 입력 capacitance 3pF 에서 80MHz 의 대역폭을 가진다. 전력 소비량은 3.3V 전원 전압이 인가된 경우 약 150mW 정도이다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.7A
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• pp.735-740
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• 2004

When optical signal power of ONU differs from each other the requirements of an OLT receiver becomes strict and the stable operation of a total PON system can't be obtained. To solve this problem each ONU channel's signal power is measured at the OLT side and control signals to equalize them are generated and sent to each ONU. The proposed scheme is tested after implementation A digital APC circuit is proposed and tested so that it can start or stop LD operation without delay. It helps other ONU to transmit signals without interference and to reduce consuming power.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.10
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• pp.2256-2262
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• 2015

Recently, device-to-device (D2D) communication has been considered as key technology for future cellular system, because it can solve the problem of excessive data traffic increment and can also provide new communication services. Herein, we propose new neighbor discovery for D2D communication and examine its performance. Our proposed scheme is proximity beacon based discovery in which wireless resource for pilot transmission is assigned based on the spatial correlation of wireless channel and sensing period is adjusted according to target accuracy such that power consumption can be reduced. The performance of our propose scheme is analyzed mathematically and verified through computer simulations.

• Proceedings of the KIPE Conference
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• 2006.06a
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• pp.438-440
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• 2006

포항가속기 연구소의 선형가속기와 빔 전송선에는 22개의 솔레노이드 전자석, 38개의 사극전자석 그리고 전자빔의 궤도 조절을 위한 29개의 2극 전자석이 있다. 전자빔의 정밀 제어를 위한 전자적 전원장치는 고정도, 고안정도 출력 특성을 가져야 한다. 이를 위하여 풀-브릿지 4-상한 DC-DC 컨버터 토플로지의 4단 병렬운전을 채택하였다. 전원장치의 입력전압은 직류 40V이고, 최대 출력전류는 직류 50A이며 그리고 스윗칭 주파수는 50 kHz이다. 고정밀, 고안정도 출력전류를 얻기 위하여 입력단의 전원 노이즈 및 전력변환부의 스윗칭 노이즈를 제거하여야 한다. 이를 위하여 채택된 low-pass 필터의 cut-off 주파수는 입력과 출력단 각각 26 Hz와 4.5 kHz 이다. 출력전류에서 전원장치로부처 발생하는 주파수 성분을 완벽하게 제거하였다. 출력전류의 분해능은 1mA 이하이며, 안정도는 10시간 이상 장시간의 경우 +/-15 ppm 이하이고 1시간 이하 단시간의 경우 +/-10ppm 이하이다. 본 논문에서는 풀-브릿지 4-상한 DC-DC 컨버터 토플로지의 4단 병렬운전을 채택한 전자석 전원장치의 구성, 특성 그리고 실험결과에 대하여 기술하였다.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.5
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• pp.25-36
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• 2016

The goal of the SmartGrid is to maximize energy efficiency by exchanging bi-directional real-time power information with the help of ICT(Information and Communication Technology). In this paper, we propose a "JRS-MS" (Joint Routing and Scheduling for Multi-channel SmartGrid) algorithm that uses numerical modeling methods in IEEE 802.11s based STDMA multi-channel SmartGrid NAN networks. The proposed algorithm controls the amount of data transmission adaptively at the link layer and finds a high data-rate path which has the least interference between traffic flows in multi-channel SmartGrid NAN networks. The proposed algorithm improve transmission performance by enhancing network utilization. By comparing the results of performance analysis between the proposed algorithm and the JRS-SG algorithm in the previous paper, we showed that the JRS-MS algorithm can improve transmission performance by maximally utilizing given network resources when the number of flows are increasing in the multi-hop NAN wireless mesh networks.