• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.167-170
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• 2005

We performed field test and analyzed results of field test in variable HFC(Hybrid Fiber Coaxial) network environments. And we investigated whether the test results is satisfied in DOCSIS(Data-over-Cable Service Interface Specification) 2.0 and OpenCable standard. Also, we propose HFC improvement problem for HFC Network quality as BcN(Broadband convergence Network) access network. We tested three sample areas. The sample areas represent various type of SO(System Operator) in korea. The field test was to measure signal level about digital channels. In results of multiple digital channels, in case of "Equalizer ON", we could be obtained very good test results. The results of field test were shown in satisfying recommended values in DOCSIS 2.0 and OpenCable. So, we could have confidence through field test that BcN will be possible to be adapted to environment of korea HFC network.

• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.277-278
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• 2009

The building that supply tidal and splash zone was constructed near Seamangeum Gate Bridge. The specimens that will be tested for maintenance of gate bridge were exposed on the tidal and splash zone, totally about 650(Fig. 1). The characteristics of strength, salt penetration profile, field application of surface repair material and section recover material will be acquired by periodical test. The program was developed to obtain optimal maintenance strategy of gate bridge as a marine concrete structure and to deposit experimental data, lab. test result, field test result, on its D/B. On this paper, we hope to introduce two years exposure data as compressive strength, the modulus of elasticity, the modulus of dynamic elasticity, field adoption of repair and recover materials. As briefly speaking the results, possion's ratio, elasticity, strength was general, but the recover materials have some problems. There was crack between concrete and recover material and delamination figures.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.8
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• pp.1186-1192
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• 2012

In Jeju Smart Grid field test, Zigbee technology is being used as one of customer side solutions for AMI. Although Zigbee networks that provides effective connectivity and control among devices are advantages in ease of implementation and use, the data can be exposed to cyber attacks such as eavesdrop, unauthorized data dissemination and forgery. Currently authentication and confidentiality services are provided with the network and link keys generated based on public key pairs that are pre-installed in offline. However, the network is vulnerable once a hacker intrudes into a local network because operation and management policies for the generated keys are not well-established yet. In this paper, the vulnerability of the Zigbee security system in the customer side environment of Jeju Smart Grid field test is analyzed. Then, two-way authentication with the unique identifiers of devices and user-specific group management policies are proposed to resolve the vulnerability.

• Journal of the Korean Solar Energy Society
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• v.26 no.3
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• pp.89-97
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• 2006

Our Housing culture continuously changes for the correspondence to social development and changes of economy, and be developing. A massive apartment complex continuously increased, and According to this in our country heating energy consumption of a residential building is continuously increasing at country me whom was limited in order to raise efficient residential land use and diffusion ratio of house. If confirm an element to be able to reduce use of a heating energy, and there is saving possibility to parts of energy saving, this study will present the standard amount used with bases to the gas amount used for heating and Field Test data about room temperature. Execute simulation with building balance (public area, a plain), the gas amount useds such as incense of a building, indoor setting temperature ($^{\circ}C$), a position of an apartment house etc. to affect the energy amount used of a valuation object building of a variable through Field Test and research on the actual condition. Calculate the standard amount used of city gas for winter season heating of a comparative analysis apartment house to data value getting the above results through Field Test and simulations with bases.

• Journal of Korean Society on Water Environment
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• v.20 no.4
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• pp.333-338
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• 2004

This study was carried out to investigate the generation and discharge characteristics of non-point pollutants from farmlands in Nak-dong river basin. Annual unit generation load of nitrogen and phosphorus by fertilization in the test paddy field was almost similar to those calculated by the fertilization standards of district agricultural technology center, but it was extremely higher in case of the test dry field. By comparing annual total generation load of nutrients from fertilization to the data of fertilizer marketing, the accurate forecasting of generation load of pollutants was achieved by marketing data. The annual total discharge ratio of nutrients through infiltration and overflow from the farmland of the test paddy field were 9.5% and 1.1%, respectively, and those in the test dry field were 22.0% and 0.1%, respectively. The monthly discharge load of nutrients were shown the highest proportioned to the discharge load from lands, but it showed higher in phosphorus, which was caused by the intermittent discharge of phosphorus accumulated in drainage.

• Journal of Environmental Science International
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• v.25 no.10
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• pp.1389-1396
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• 2016

A monitoring system for a field magnetometer was configured with assistance of a Raspberry Pi as a data logger. The suggested geomagnetic system uses a semi-real-time data transmission module. The system consists of two parts: a field-observation part and a data-center part. The field-observation part comprises a Raspberry Pi, magnetometer, LTE router, and power source, while the data center part takes samples at the site. The collected magnetometer data are then sent to the data center through the LTE router. The newly designed monitoring system was deployed and checked in Jeju-do island, and found to operate stably. The suggested system is promising in that it is simple and cost saving, providing at least physical insight and knowledge on the complex natural phenomena.

• Wind and Structures
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• v.4 no.2
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• pp.101-118
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• 2001

This paper reports the field measurements concerning pressure equalization of rainscreen facades carried out at the Technical University of Eindhoven (TUE) in the Netherlands. The field facility including the details of test panel, meteorological tower, instrumentation, data collection and analysis is presented. Results of investigations into cavity response for various leakage and venting configurations are discussed. Frequency domain techniques have been utilized to show the influence of wind as well as facade characteristics on the pressure equalization performance. Further, this paper presents an early attempt to synthesize the experimental results into existing building codes.

• International Journal of Highway Engineering
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• v.8 no.3 s.29
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• pp.115-127
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• 2006

The purpose of field monitoring system in KHC-Test Road is to provide the performance data for environmental loadings from pavement surface. Among them, water content reflectometer(WCR) are used for measuring the volumetric water content of pavement subgrades. However, WCRs are not well-calibrated based on the local field conditions. A need therefore exists for improving equations for predicting water content using the proper field and laboratory calibrations. Based on the study performed, calibrations based on various soil characteristics and density conditions are well fitted to the data from fields. So, it is recommended to use the suggested general calibration of WCR to the compacted subgrade soils in test road for predicting the volumetric water content.

• Proceedings of the Safety Management and Science Conference
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• 2007.04a
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• pp.309-322
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• 2007

This paper shows application guide of dependability data from the field, life cycle costing, and maintainability. Moreover, this study introduces mathematical expressions and predictions for reliability, availability and maintainability. This paper also shows compliance test procedures for steady-state availability, and application of Markov techniques.

• Journal of the Korean Society for Railway
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• v.5 no.2
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• pp.104-111
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• 2002

The purpose of interlocking system was to prevent the route for a train being set up and its protecting signal cleared if there was already another, conflicting route set up and the protecting signal for that route cleared. This paper proposed Interlocking Inspection System(IIS) consisting of interlocking simulator and field simulator to operate interlocking test of computer based Electronic Interlocking System(EIS) in this paper. Interlocking simulator consists of Design Edit System(DES), Logical Database Management Tool(LDMT) and real-time confirming system, field simulator is a equipment to simulate a control object of EIS and constitutes configuration operated in 19 inch standard rack. As a result of test to prove capacity of this IIS, the efficiency was shown as excellent. Therefore by using inspection system, we obtain every advantages. It has the functions for test data generation and automatic test execution based on personal computer. Time and cost for test work can be reduced more efficiently by using this developed inspection system