• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.8B
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• pp.1456-1463
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• 1999

This paper describes the measurement system of antenna factor using standard antenna method in OATS(Open Area Test Site) of KRISS(Korea Research Institute of Standards and Science) and methods for reducing an environmental noise affecting antenna factor. The range of measurement frequency is 30 - 1000 MHz, all control and data acquisition were done by computer automatically. Measurement results of antenna factors are presented, total uncertainty of antenna factor is $\pm$1 dB.

• Journal of Wetlands Research
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• v.16 no.2
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• pp.161-171
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• 2014

Recession of hydrograph gives a significant contribution to estimation of baseflow using rainfall-runoff models and baseflow separation methods, because recession affects baseflow. This study attempted to enhance the accuracy of streamflow predictions using a Soil and Water Assessment Tool (SWAT) model and to separate baseflow from the predicted streamflow. For this, this study used two scenarios: 1) to calibrate eleven parameters using an auto-calibration tool with the alpha factor obtained from RECESS (S1); and 2) to calibrate twelve SWAT parameters including alpha factor (one of SWAT parameters) using an auto-calibration tool (S2). Then, baseflow spearation from the predicted streamflow was conducted by using Web-based Hydrograph Analysis Tool (WHAT). The results show that there is no significant difference between Nash-Sutcliffe efficiency (NSE) values of S1 and S2 for calibrations to streamflow. However, calibrations to baseflow showed that NSEs are 0.777 for S1 and 0.844 for S2, which means a significant difference. Quantitatively compared to the observed streamflow, relative errors were 20.78 % for S1 and 6.59 % for S2. Finally, this study showed the importance of recession in baseflow separated from the predicted streamflow using a rainfall-runoff model.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2004.04a
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• pp.83-89
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• 2004

The electronic distance measurement instrument, first introduced in the 1950s has, since those early days, undergone continual refinement. Rapid advances in related technologies have provided lighter, smaller and more precise equipment. Understanding for the principle, the standardized observation technique and the precision of EDM instrument is mostly important to improve the quality and the reliability of by-product in the field of engineering and industrial surveying. Simple and accurate calibration is regularly and periodically necessary to maintenance the precision of EDM instrument. This paper describes the calculated example of zero error and scale error as a correction of EDM by applying the least square method to baseline observations. Here we deals also with the testing criteria for precision instrument testing according to different types of EDM instruments.

• Journal of Sensor Science and Technology
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• v.17 no.3
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• pp.188-194
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• 2008

For the accurate calibrations of thermometers at low temperatures, triple points of oxygen and argon have been realized using sealed-type triple point cells. The triple points were realized with both adiabatic and continuous heating methods. The resistance of three capsule-type standard platinum resistance thermometers were measured at the triple points of oxygen, argon, mercury and water for the calibrations of these thermometers in the range from $-220^{\circ}C$ to $0.01^{\circ}C$. The extended uncertainty, with the coverage factor of 2, of the calibration in this range is smaller than 1 mK.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2006.08a
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• pp.70-70
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• 2006

• Journal of Environmental Impact Assessment
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• v.22 no.6
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• pp.695-703
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• 2013

Soil erosion and sediment delivery ratio(SDR) were estimated by using HSPF model in 3 tributaries of upper stream of Geum river-basin. Meteorological data and other input data were constructed from 2006 to 2011 year by the HSPF model. Flow and suspended solid results were relatively matched with the measurement data through the calibration and validation of the model. Soil erosion was proportional to the amount of rainfall and the area of watershed based on the results of model calibration and validation. SDR in Moojunamdea stream was the highest and one in Cho stream was the lowest. This was effected by the geographical characteristic. SDR was 17.6% Moojunamdea stream, 9.1% Cho stream and 13.2 % Bocheong stream. As the SDR was effected by watershed area and shape factor in this study area.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.206.2-206.2
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• 2014

Recently, particle induced X-ray emission (PIXE) analysis system was installed at the 2MV ion acceleration system in Korea institute science and technology (KIST). This installation is for complement to low atomic resolution of heavy atoms at Rutherford backscattering spectrometry (RBS) system. For quantitative analysis, a mass calibration of the PIXE set-up has been done with thin film standards and. The GUPIX software package has been used to process the PIXE spectra and the results are compared with the values from RBS system. Therefore, the instrumental constant H (solid angle and correction factor) is determined relying completely on the GUPIX data base (cross-sections, fluorescence and Coster-Kronig probabilities, stopping powers and attenuation coefficients) for a large set of elements. These H values can be used in future analysis.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.17 no.3
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• pp.47-52
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• 2008

The force transducer in the acceleration plant due to dynamic fracture is calibrated by dynamically using the stress pulses from a longitudinal bar. The bar is supported by two strings attached to the ceiling. The bar velocities before and after impact are measured and a full bridge at bar and transducer is formed by the four strain gauges. A transient recorder is used to store the stress pulse signals of force transducer and bar. For the first test series, three point bend test specimens can be chosen by means of test rig design and the inspection as sample experiment in this presented paper is sufficient for proving with the numerical simulation of the specimen model.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.05a
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• pp.298-302
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• 2002

Equivalent volume estimation of the coupler and two coupled microphones has a key role in standard microphone pressure calibration. The equivalent volume of the microphone is determined by the dynamic characteristics of the diaphragm system and front cavity. Therefore the modal parameters of diaphragm system - natural frequency and damping fatter - should be measured explicitly for the estimation of the equivalent volume. The diaphragm system is composed of the vibrating diaphragm, back slit behind diaphragm, pressure equalization vent, and front cavity which are acoustically coupled. In the measurement, the electrostatic actuator was used to excite the system with the swept sine, and the frequency response was obtained. The close actuator in front of the diaphragm must influence the radiation impedance of the system, and then the modal parameters. From the measured frequency response, the natural frequency and the damping factor could be estimated with the Complex exponential method based on the Prony model and the zero crossing real and imaginary plot.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.03a
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• pp.490-495
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• 2009

In this study, estimate solution of ultimate axial capacity for axial loaded pile is proposed using step-wised shape. This is verified for effective appling on realistic factor by calibration chamber tests. Estimation method of ultimate axial capacity in this study is verified by calibration chamber test. The results of ultimate axial capacity through this proposed method have sufficiently low standard derivations and COVs. Also, this is verified through test that method is similarly resulted with measured values.