• Tribology and Lubricants
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• v.29 no.3
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• pp.160-166
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• 2013

There is an indispensable need for force calibration for quantitative nanoscale force measurement using atomic force microscopy. Calibrating the normal force is relatively straightforward, whereas doing so for the lateral force is often complicated because of the difficulty in determining the optical lever sensitivity. In particular, the lateral force calibration of a colloidal probe in a liquid environment often has a larger uncertainty as a result of the effects of the epoxy, the location of the colloidal particle on the cantilever, and a decrease in the quality factor. In this work, the lateral force of a colloidal probe using a reference cantilever with a known spring constant was calibrated in a liquid environment. By obtaining the spring constant and the lateral sensitivity at the equator of a spherical colloidal particle, the damage to the bottom surface of the colloidal particle could be eliminated. Further, it was shown that the effect of the contact stiffness on the determination of the lateral spring constant of the cantilever could be minimized. It was concluded that this method can be effectively used for the lateral force calibration of a colloidal probe in a liquid environment.

• Analytical Science and Technology
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• v.8 no.4
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• pp.731-738
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• 1995

Toxic air pollutants are investigated in a petrochemical industrial park in Taiwan by using a movable open path FTIR. The results show the qualitative and quantitative analysis of emission gases from plants, and also provide the emission rate of different compounds. More than twenty compounds under usual operation are found from this industrial park. The concentration variation with time can be correlated exactly with wind direction. It means that by changing the measuring points, the source of emission can be unambiguously identified. An EPA proved PAL model is applied to estimate the emission rate of either a point or an area source. Local atmospheric stability is determined by releasing the $SF_6$ tracer. The origins of errors come mainly from the uncertainty of source's configuration and the variation of meteorological condition. Through the continuous measurement (half an hour base in this study) of OP-FTIR sensor, the maximum value of emission rate and the annual amount of emission can be derived. The emission rate of the measured toxic gases are derived by the model technique and the results show that the emission amount are in the order of ten to hundred tons per year.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.43 no.10
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• pp.896-901
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• 2015

The skin-frame type structure is designed to investigate the thermal deformation of the wing skin induced by the temperature gradient. In order to effectively simulate the temperature gradient on the wing specimen, a water cooling system is devised on the frame of the specimen. Out of surface skin deformation of the skin-frame type structure made of SUS304 material with respect to the temperature is successfully measured using the digital image correlation (DIC) technique including quantitative evaluation of the measurement uncertainty.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.03a
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• pp.444-455
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• 2009

Great concerns on geotechnical risk & hazard assessment have been increased due to human and economic damage by natural disasters with recent global climate changes. In this paper, geotechnical problems in particular, landslides which is interested in European countries and North America, were mainly discussed. For these, 18 key topics on geotechnical risk and hazards which had been discussed at the LARAM 2008 workshop in Italy were analyzed after grouping by subjects. Main topic contents consisted of applications such as field measurement, early warning systems, uncertainty analysis of parameters using radar, optical data and statistical theory and so on. And the problems related to analysis of vulnerability and deformation due to earthquakes, investigation of gas zone using seismic reflection data in a landslide area, risk quantification and hazard assessment of landslide movements and multi-dimensional analysis for stability of complex slopes were attracted. Also, there were studies on risk matters of cultural heritage, the blockglide of clayey ground, simulations of debris flows based on GIS, quantification of the failure processes of rock slopes, a meshless method for 3D crack modelling, and finally risk assessment for cryological processes due to global warming.

• Bulletin of the Korean Chemical Society
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• v.31 no.11
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• pp.3228-3232
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• 2010

Malachite green (MG) has been used world-widely in aquaculture as a parasiticide or fungicide. Although MG performed successfully, it has not been permitted for use in aquaculture from European Union, USA, and Canada because of its carcinogenicity and mutagenicity. We developed a sensitive and specific method to determine MG and its principal metabolite, leucomalachite green (LMG), respectively by isotope dilution liquid chromatography mass spectrometry (ID-LC/MS). To enhance the extraction recovery of MG and LMG from fish tissue, an additional step, saponification, was introduced in sample preparation process to remove fat in sample extract, which hampered the performance of SPE columns. The residue of MG and LMG in fish was analyzed using liquid chromatography mass spectrometry in the selected ion monitoring (SIM) mode by monitoring at m/z 329 and 334 for MG and $d_5$-MG and at m/z 331 and 337 for LMG and $^{13}C_6$-LMG, respectively. This method was validated by comparing with the value of the reference material provided by Laboratory Government Chemistry (LGC). The results agreed within the measurement uncertainty and the accuracy was much improved than the provided reference value by LGC.

• Journal of Electrical Engineering and Technology
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• v.13 no.2
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• pp.911-917
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• 2018

Influence of the adaptors on the calibration of $100{\mu}H$ inductance standard was studied as a function of torque, applied when tightening the standard inductor terminal with the adaptor. Two different homemade adaptors of BPO gold-plated brass (BPO-Au) and banana-copper (BN-Cu) were made for the connection between the LCR meter and the inductance standard. The measured inductance (L) of the standard inductor and the contact resistance ($R_C$) between the adaptor and the standard inductor terminal showed exponential decreases against the torque increase from $25cN{\cdot}m$ to $150cN{\cdot}m$. The measured L and the calculated equivalence series resistance ($R_S$) were dependent on the adaptor type as well as on the $R_C$. The results of the adaptor analysis imply that the BPO-Au adaptor with the lower $R_C$ is more suitable for the inductance calibration. The calculated inductance of $99.956{\mu}H$ corrected by subtraction of the adaptor inductance and the contact resistance contributions from the measured value using the BPO-Au adaptor agreed well with the certificate ($99.948{\mu}H$) of the PTB within the measurement uncertainty of $140{\mu}H/H$.

• Korean Journal of Optics and Photonics
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• v.12 no.4
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• pp.300-304
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• 2001

We suggest a method to measure and correct bending deformation in piezoelectric ceramics displacement. The angle and direction of the bending deformation are measured by monitoring the position of a laser beam reflected on a mirror which is attached to the piezoelectric ceramics with the uncertainty of the angle measurement of $0.36\mu$rad. We divided the electrode of a piezoelectric ceramic into 3 parts and connected 3 capacitors to each electrode in order to apply different voltage to each electrode with one voltage supplier. The deformation was corrected by adjusting the capacitance of each capacitor and was reduced to 6.3%, comparing to the uncorrected case. By using this corrected piezoelectric ceramic to modulate the length of the ringdown cavity, the fluctuation of the decay time caused by the change in optic axis of the cavity was removed.emoved.

• Proceedings of the Korea Contents Association Conference
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• 2016.05a
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• pp.241-242
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• 2016

Recent abnormal climate change induces localized heavy rainfall and extreme disasters such as debris flow near urban area. Thus many researches have been conducted to estimate and prevent, especially in focus of physical behavior of debris flow. Even though it is hardly to consider overall related parameters to estimate the extent and degree of directly or indirectly damages due to debris flow. Those analytic restraint would be caused by the diversity and complexity of regional topographic and hydrodynamic characteristics of debris flow inside. We have utilized the Bayesian method to compensate the uncertainty due to the complex characteristics of it after analyzing the numerical results from FLO-2D and field measurement data. Revised values by field measurements will enhance the numerical results and the missing parameters during numerical simulation will be supplemented with this methodology. As a final outcome in this study, the risk index of debris flow damage will be suggested to provide quantitative estimation in terms of hazard protection including the impact on buildings, especially in inner and outer of urban area.

• Journal of Electrical Engineering and Technology
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• v.13 no.2
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• pp.669-676
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• 2018

Transmission system has been well studied since long time and power system techniques of distribution system are more or less derived from transmission system. However, unlike transmission systems, many practical issues are encountered in the distribution system. Considerable amount of error is observed in voltage obtained from the Feeder Remote Terminal Units (FRTUs) measured by the pole mounted PTs along the distribution feeder. Load uncertainty is also an issue in distribution system. Further, penetration of Distributed Generators (DGs) creates voltage variations in the system. Hybrid radial/ loop distribution system also make it complicated to handle distribution system. How these constraints to be handled under Distribution Automation (DAS) environment in order to obtain error free voltage is described in this paper and therefore, a new approach of voltage error correction technique has been proposed. The proposed technique utilizes reliable data from substation and the FRTUs installed in DAS. The proposed technique adopts an iterative process for voltage error correction. It has been tested and proved accurate not only for conventional radial systems but also for loop distribution systems.

• The Journal of the Acoustical Society of Korea
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• v.36 no.3
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• pp.202-210
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• 2017

For the target tracking in cluttered environment using a bistatic sonar whose transmitter and receiver are separately positioned, it is necessary to use data association algorithm via applying a proper measurement modelling to the bistatic sonar. The measurements obtained from the interval of ownship's maneuver have an increased error due to uncertainty of the position of transmitter and receiver. Using the measurements from this interval results in poor target tracking performance. In this paper, an improved tracking performance for the proposed data association based multiple model algorithm is validated by a monte carlo simulation.