• Aerospace Engineering and Technology
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• v.5 no.2
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• pp.16-26
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• 2006

GNSS is a satellite-based radio navigation aid. For using it in civil air navigation area, any GNSS service should meet the requirements of accuracy, integrity, continuity and availability in each flight phase established by ICAO. In this study, a remote integrity monitoring system(RIMS) for GNSS are proposed and explained to utilize it in the design of GNSS augmentation system such as GBAS and GRAS. The RIMS consists of signal-in-space receiving subsystem and signal processing subsystem. Each GPS receiver is connected to Host PC by the serial to ethernet converting device which is able to convert serial port connection to LAN port connection in order to exchange information via the internet. We can overcome the siting limitation of GPS receiver and antenna, and reduce signal loses in the cable between GPS antenna and receiver. This system is providing the development environment for GBAS CAT-I system.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.7
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• pp.1579-1588
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• 2014

The LAN method is the most widely used in domestic high-speed internet access and rapidly moving to 1 Gbps Ethernet from 100 Mbps one to provide high-speed services such as UHD TV. The 1000BASE-T PHY with 4 pairs UTP transmits a PAM-5 signal at the 125 MHz clock per each pair to achieve 1 Gbps rate. In order to correct errors over the channel, the transmitter uses a TCM which is combined the convolutional encoder and PAM-5, and the receiver uses the Viterbi decoder. In this paper, we implement a Viterbi decoder which can correct two pair errors and operate at the least 125 MHz clock speed. Finally, we will verify the error correction function and the operating speed of the implemented decoder with a logic analyzer.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.10
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• pp.2006-2013
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• 2015

In this paper we propose a multi-protocol gateway system based on low power wireless communications. The proposed multi-protocol gateway system was designed to allow real-time monitoring and control of the on-site situation through wired and wireless networks by gathering information for streetlight power control and environmental monitoring. The sensing data using multi-sensors with composite processing that selectively used wired or wireless communication (e.g., CDMA, Ethernet (TCP/IP), GPS, etc.) were designed to act as intermediaries that transmitted to the main server through ZigBee. Inaddition, they were designed by separating a CPU board and baseboard to ensure low maintenance cost and ease of hardware replacement. The proposed multi-protocol gateway system's power, impact, continuous operation stability, and immunity test results obtained a normal operation success rate of over 95% and normal continuous operation results. Moreover, in the voltage drop test, instantaneous immunity test, and conductive RF electromagnetic field immunity test, it obtained an average rating result of "A".

• Journal of Digital Convergence
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• v.11 no.11
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• pp.85-94
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• 2013

This paper presents a novel mobile measurement system with multi antennas which enable mobile measurement as well as fixed measurement with telescope mast. Proposed system installed 4 omni directional antennas for the space diversity process and one directional log periodic antenna for the simultaneous conventional fixed measurement. Whole antenna systems are connected to the custom DTV channel analyzers with Ethernet networks respectively and processed by the main controller to calculate real time average receive levels. To prove the performance of proposed system, the typical receive models are categorized as 3 area types - open area, building area and house area, and then intensive field tests were performed through mobile and fixed measurement phases. With these measurement data, the relationships between mobile and fixed measurement are analyzed, and the concept of compensation factor is proposed to assume the average receive level of signal. The field test is fulfilled as a co-work with public broadcasters and the proposed system is applied to the intensive coverage measurement projects for metropolitan areas by the korean government agencies.

• Journal of Bio-Environment Control
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• v.18 no.2
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• pp.87-94
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• 2009

This study was conducted to develop an automation system of inoculation processing of a lily callus. The results are summarized as followings: The end-effector was manufactured as suction and machine type. And these end-effectors can separate the callus from the mediums and divide the separated callus and then inoculate the divided callus to new mediums. Using the machine type end-effect0r, the results of the experiment showed the success rate in the division process was 100% while the separation and inoculation process was 92%. To develop the automation controller of inoculation process, the system was developed to control an external device and the manipulator. The data communication program between a robot and a personal computer was also developed using CAsyncsocket and Ethernet Interface.

• Journal of the Korea Society of Computer and Information
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• v.18 no.5
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• pp.9-17
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• 2013

This paper presents the design of the educational router system. This system is designed and implemented to support network configuration and embedded programming technology of the user on Internet. Not only Static routing protocol but also a kind of dynamic routing protocols such as OSPF and RIP and firewall have been programmed for education based on ethernet interface. ADS 1.2 as debugging environment, uC/OS-ii as RTOS and C language as development language are used. The educational procedures is compile, loading of static routing protocol, a kind of dynamic routing protocols such as OSPF and RIP and firewall program already supplied. Thereafter the verification is checked by using "ping" test to allow for demo operation such as hands-on training procedure. Finally programming procedure similar with demo operation of static routing protocol, a kind of dynamic routing protocols such as OSPF and RIP and packet filtering function is educated step by step.

• Korean Journal of Optics and Photonics
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• v.19 no.5
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• pp.343-348
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• 2008

This study was carried out to commercialize FTTH by developing a burst mode optical receiver for E-PON. The optical receiver was manufactured by minimizing the capacitance of a photodiode to improve sensitivity for meeting 10, 20 km OLT Rx standard of E-PON at the transmission speed of 1.25 Gb/s. When bit-error ratio is $10^{-12}$ and PRBS is $2^5-1$, sensitivity is -26 dBm, loud/soft ratio is 23 dB. Both preamble time and guard time were set to 102.4 ns (128 bit). After comparing a photodiode whose capacitance is 0.53 pF with another photodiode whose capacitance has been minimized to 0.26 pF, we could see that sensitivity improved to 0.7 dBm and so did bandwidth to 190 MHz of burst mode for the optical receiver manufactured by the photodiode whose capacitance is 0.26 pF.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.42 no.12
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• pp.45-52
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• 2005

This paper proposes low latency handover procedure for seamless connectivity and QoS support between wired (e.g. Ethernet) and wireless (e.g. WLAN, WiBro(802.16-compatible), CDMA) networks by the mobile-assisted and server-initiated handover strategy. It is assumed that the server decides the best target network considering network status and user preferences. In this procedure, a mobile terminal associates with the wireless link decided at the server in advance and receives CoA as well. When handover occurs without the prediction in wired networks, the server performs fast binding update using physical handover trigger through the MIH (media independent handover) function. As a result, a mobile terminal does not need to perform L2 and L3 handover during handover so that this procedure decreases handover latency and loss.

• Journal of the Institute of Electronics Engineers of Korea TE
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• v.39 no.2
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• pp.95-103
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• 2002

We know that the all of warfare system has been becoming complex and variety in warfield thru the Gulf-War. The all of warfare electronic systems is designed to inter-operate by networks in recently. Especially Warfare Equipment systems of Men-of-War(War ship) as like KDX(Korea Destroyer, Experimental), FF(Frigate), PCC(Costal Patrol Craft), Submarine are connected by Combat System Databus to the Command system(C2 System), so C2 system can control all of equipments in ship. In this view, the status of network(Combat System Databus) is very critical parameter in war field. So In this paper, we propose the method of Network Management System construction for War ship, and especially propose the architectural design of network management system for DX(Destroyer, Experimental) equipments using SNMP(Simple Network Management Protocol). And Link Utilization is monitored by simulation. 

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.12
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• pp.63-72
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• 2007

This paper addresses the system development that can transfer data and TDM signals simultaneously by adding TDM pseudowires functions to E-PON system. E-PON technology is one of many technologies which can realize FTTH, has raised as next generation access network solution having both low-cost Ethernet technology and optical infrastructure. TDM pseudowires service is the new voice/data conversion technology which can transfer the existing TDM circuit switched voice and data over packet switching network. In this paper, this system can provide both data and TDM service without deteriorating QoS by adding TDM pseudowires service module to E-PON, and then implementing QoS control function. Therefore, the competitive system which can transfer both data and TDM signal, can be installed.