• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.711-716
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• 2010

This study selected the promising area of submarine groundwater discharge(SGD) that flows into the sea following unconfined physical aquifer through the electrical resistivity survey of the land and sea. The submarine groundwater discharge(SGD) mostly flows into the sea following fracture zones, and the detection of the fault zone becomes the important guideline of groundwater discharge. Electrical sounding of the land assessed the groundwater flow and integration possibility according to the location of a fault that is a water path between underground reservoir and surface water as well as a rock fracture. In addition, the study conducted sea electrical resistivity to expand the area with high potential and selected the expected water potential groundwater area. The areas of the study were Busan and coastal areas, and for the terrain analysis, the candidates of the ground exploration were selected after analyzing lineaments that is expanded to coast direction.

• Journal of the Korean Ceramic Society
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• v.44 no.12
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• pp.720-726
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• 2007

Current collectors of SOFC play a significant role on the performance of power generation. In this study a single cell stacked SOFC was assembled using Ag-mesh as a cathode current collector, and evaluated its performance. No gas leakages of the single cell stack occurred in the tests of gas detection and OCV measurement. The OCV and initial power of the stack were 1.09V and $0.45W/cm^2$, respectively, under the flow rates of air at 2,500 cc/min and $H_2$ at 1,000 cc/min at the test temperature of $750^{\circ}C$. A degradation rate of 44.0% was measured during the prolonged time of 307 h. The relatively low durability of the tested single cell stack was found to be the evaporation of Ag-mesh at the current corrector.

• KSBB Journal
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• v.27 no.3
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• pp.167-171
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• 2012

A convenient liquid chromatographic enantiomer separation of several ${\alpha}$-amino acid esters as benzophenone Schiff base derivatives on covalently immobilized chiral stationary phases (CSPs) derived from polysaccharide derivatives was developed. The benzophenone imine derivatives of ${\alpha}$-amino acid esters were readily prepared by stirring benzophenone imine and the ${\alpha}$-amino acid ester hydrochloride salts in 2-propanol. The chromatographic conditions used on all CSPs were 0.5% or 5% 2-propanol/hexane (V/V) as the mobile phases at 1 mL/min of flow rate and UV 254 nm detection. The performance of Chiralpak IC among all CSPs was superior to that of the other CSPs for resolution of benzophenone imine derivatives of ${\alpha}$-amino acid esters. It is expected that the developed analytical method will be useful for enantiomer resolution of other ${\alpha}$-amino acid esters as benzophenone Schiff base derivatives.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.30 no.7
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• pp.417-422
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• 2017

A high-performing photoelectric device was realized for the $MoS_2$-embedded Si device. $MoS_2$-coating was performed by an available large-scale sputtering method. The $MoS_2$-layer coating on the p-Si spontaneously provides the rectifying current flow with a significant rectifying ratio of 617. Moreover, the highly optical transmittance of the $MoS_2$-layer provides over 80% transmittance for broad wavelengths. The $MoS_2$-embedded Si photodetector shows the sensitive photo-response for middle and long-wavelength photons due to the functional $MoS_2$-layer, which resolves the conventional limit of Si for long wavelength detection. The functional design of $MoS_2$-layer would provide a promising route for enhanced photoelectric devices, including photovoltaic cells and photodetectors.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.12
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• pp.82-87
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• 2016

The photoplethysmogram (PPG) signal is one of the mainly considered bio signals along with the electrocardiogram (ECG) signal. PPG signals can be used to estimate the speed of flow of blood in vein, saturation of peripheral oxygen and etc. The heartbeat rate is a common feature in order to evaluate those checkup lists. To estimate the correct heartbeat rate, dynamic noises must be removed in the PPG signal. Conventionally, the acceleration signal is used to remove dynamic noises. This method, however, increases the computational complexity. In this paper, we proposes a solution that uses only PPG signals to calculate the heartbeat rate, and which can be used as a basement in real-time healthcare solution.

• Journal of Sensor Science and Technology
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• v.20 no.6
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• pp.400-405
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• 2011

This study introduced the development of a strip type disposable enzyme-linked immunosensor platform for the detection of IgG. Strips of the strip sensor were fabricated by using commercial nitrocellulose filter membranes and a housing holder for the strips was manufactured by using a standard injection molding process for a plastic material. An IgG-urease conjugate was prepared and used for the competitive immune-binding with sample IgG. From the enzymatic reaction between the conjugated urease and urea added, ammonia was generated and caused a localized alkaline pH change on the immobilized antibody band which was coated onto the sensor strips. This pH increase subsequently caused a color change of the antibody band in the presence of a pH indicator, phenol red. Used in conjunction with a competitive immunoassay format, the intensity of the color produced is directly linked with the concentration of target analyte, IgG, and specific measurement of IgG in a lateral flow immunoassay format was achieved over the range 100 ppb to 2000 ppb IgG.

• Journal of the Korean Institute of Telematics and Electronics C
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• v.35C no.11
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• pp.48-56
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• 1998

In this paper, a moving object detection and face region extraction algorithm which can be used in video monitoring systems is presented. The proposed algorithm is composed of two stages. In the first stage, each frame of an input video sequence is analyzed using three measures which are based on image pixel difference. If the current frame contains moving objects, their skin regions are extracted using color and frame difference information in the second stage. Since the proposed algorithm does not rely on computationally expensive features like optical flow, it is well suited for real-time applications. Experimental results tested on various sequences have shown the robustness of the proposed algorithm.

• Journal of Electrical Engineering and Technology
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• v.11 no.3
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• pp.683-689
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• 2016

Most outdoor solid insulators may suffer from surface degradations due to non-stationary currents that flow on the insulator surface. These currents may be classified as leakage, discharge and tracking currents due to their disturbing potencies respectively. The magnitude of these currents depends on the degree of the contamination of surface. The leakage signals are followed by discharge signals and tracking signals which are capable of forming carbonized tracking paths on the surface between high voltage and earth contacts (surface tracking). Surface tracking is one of the most breakdown mechanisms observed on the solid insulators, especially polymers which may cause severely reduced lifetime. In this study the degradations observed on polyester resin based insulators are investigated according to the IEC 587 Inclined Plane Test Standard. The signals are monitored and recorded during tests until surface tracking initiated. In order to prevent total breakdown of an insulator, early detection of tracking signals is vital. Continuous Wavelet Transform (CWT) is proposed for classification of signals and their energy levels observed on the surface. The application of CWT for processing and classification of the surface signals which are prone to display high frequency oscillations can facilitate real time monitoring of the system for diagnosis.

• Journal of Korean Society for Atmospheric Environment
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• v.15 no.3
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• pp.327-333
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• 1999

Determination of chloride ion in concentrated NaOH solution by capillary electrophoresis has been studied. The analysis was performed by indirect UV absorption detection using chromate buffer at 254nm. The matrix effect of the sample has been observed so that the sensitivity in strong NaOH solutaion has decreased up to 10% of that in distilled water. The pH effect of the sample on the sensitivity of CE peaks has been investigated. The method for increasing the sensitivity have been investigated and the optimum pH and concentration of the buffer were 7.5 and 10mM, respectively. A cationic surfactant cetyltrimethylammonium bromide(CTAB), was added to a buffer solution in order to reverse the electroosmotic flow(EOF) in the capillary. This results in a short analysis time and better peak shapes. Using this optimum condition, the determination of chloride ion in real environmental sample has been performed, which is captured in strong NaOH absorbent prepared for absorbing gas from chimney. The standard addition method has been applied for the quantitative analysis, and it was obtained the good reproducibility.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.10a
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• pp.929-932
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• 2007

The integrated prevention of disaster management system is collected prevention of disaster data from prevention of disaster relation other systems and smart sensor in USN. This system manages fire fighting facility effectively. The relation equipment which is used in existing and network using "Open Protocols" about under using the support system which is integrated effectively as the destroyer. It connects CCTV, the sensitivity environmental sensor, automatic fire detection equipment and security equipment and air flow equipment system using Internet. The System Server was collected monitoring data at the each equipment and processing by operational scenario. It will verified the effectiveness of operational scenario and integrated prevention of disaster management system