• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.4
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• pp.102-109
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• 2006

In this paper, the system level EMC radiated emission test results of KoDSat(Korea Demonstration Satellite), its affects upon the Launch vehicle and H/W improving methods regarding its over exceed value of EMC specification are discussed. Regarding its over exceed value, we estimated that DAU of KoDSat generated the exceeded EMC noise source, and these test results were analyzed using the EMC2000 tool to find out how did it affect the FTS(Flight Termination Subsystem) of KSLV-1(Korea Small Launch Vehicle). To diminish the EMC noise source of UHF(430.1Mhz) band level, we redesigned the DAU power board to be applied the various schemes for EMI noise reduction such as grounding, shielding and EMI filtering, and also verified these reworks to analyze its diminishing affects in UHF band level by means of performing the DAU box level EMC test and performing the second KoDSat's system level EMC test.

• Journal of Advanced Marine Engineering and Technology
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• v.32 no.1
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• pp.153-161
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• 2008

Recently, the research and development of the fish cage in open sea from domestic is active and it is almost complement with commercial scale test on 'seogwipo'. But domestic technology is not sufficient of management RMS(Remote Monitoring System) with advanced country, so it is difficult to maintenance and monitor fish cage in open sea. This paper introduces a fish cage environmental monitoring system for measuring pH, DO and temperature. A signal is treated with DAU(Data Acquisition Unit) by a wireless communication method and transfers data to host computer for data processing. These data are graphically shown on the monitor with LabVIEW program and logged on the data processing system in the form of file.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2006.06a
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• pp.273-274
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• 2006

The sea is origin of all lift, and 90% of the all living organisms are in the sea. The biosynthesis is very different. Many organisms are kept on a lower or developed to another evolutionary level than on shore. Our society is increasing demand and need for marine food and this food has to product at onshore or offshore fish farming sites. Ocean fish farms have a special operation properties such as a good quality water, net cage, sheltered locations and feeding system. The farming site is controlled and monitored for fish welfare as ammonia($NH_3$), temperature, the speed of a running fluid. Specially, the fish farm is seriously influenced by ammonia. In this paper, $NH_3$ monitoring system for ocean fish farm is researched for the suitable fish farming sites, and test equipment is designed for achieving practical data. The equipment wit monitoring algorithm is expected to the useful system for ocean fish farm.

• Proceedings of the KIEE Conference
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• 2003.07c
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• pp.1626-1628
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• 2003

The lightning arrester is a very important overvoltage protection device in the electric power system. Therefore, the inspection of lightning arrester whether it keeps its performance or not properly has close related to verifying the safety confidence of the electric power system. But the development of the deterioration measuring method and on-line detecting system, is necessary to monitor the deterioration of the lightening arrestor. In this paper, we developed the lightning arrester degradation monitoring system. This system detected leakage current of lightning arrester by using the ZCT, and analyze the third harmonics ingredient of leakage current using DFT method in the Data Acquisition Unit(DAU). The analyzed current signal is transmit to the Human-Machine Interface(HMI), and HMI alarmed when accident are occurred and informed with the amplitude of leakage current to the operator.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1732-1737
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• 2004

This paper proposes Internet-based checking technique for machine-tools with variant CNC (Computerized Numerical Controller). According to the architecture of CNC, CNC is classified into two types such as CAC (Closed Architecture Controller) which is conventional CNC, and OAC (Open Architecture Controller) which is a recently introduced PC-based controller. CAC has a closed architecture and it is dependent on CNC vender specification. Because of this, it has been very difficult for users to implement an application programs in CNC domain. Therefore, an additionally special module is required for Internet-based application such as remote checking. In this case, web I/O embedded module can be efficiently applied for Internet-based checking. The module is directly attached to TCP/IP network for communication. In order to obtain the monitoring data of CNC machines, the I/O signals of the module are assigned to PLC (Programmable Logic Controller) input and output (I/O) signals within CNC domain. On the other hand, OAC has a PC-based open architecture and an additional module is not necessary for the connection with external site. Because of this, a simple DAU is just used for signal sensing and data acquisition without additional communication modules. For Internet-based remote checking of machine-tools with OAC, a user-defined daemon and application programs are implemented as the form of internal function within the PC-based controller. Internet communication is performed between the daemon program in CNC domain and web script programs in external server. Checking points defined in this research are classified into two categories such as structured point and operational point. The formal includes the vibration of bearing, temperature of spindle unit and another periodical management. And the latter includes oil checking, clamp locking/unlocking and machining on/off status.