• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.04a
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• pp.242-246
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• 1996

Accurate measurements of burr profile and burr size are very important for the automation of deburring. In this paper, a new burr measurement system using capacitance sensor is proposed. Ultra precision milling machine was used as a sensor positioning system. The possibility and limitation of employing a capacitance sensor to defect burrs are also investigated. The proposed system is proven to be relatively accurate, easy to setup and lower cost. This system will be applicable to a fully automated deburring system with minor modifications.

• Korean Journal of Metals and Materials
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• v.47 no.5
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• pp.311-315
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• 2009

2-dimensional (2D) dopant profiling in semiconductor device was carried out by electron holography and scanning capacitance microscopy methods with the same multi-layered p-n junction sample. The dopant profiles obtained from two methods are in good agreement with each other. It demonstrates that reliability of dopant profile measurement can be increased through precise comparison of 2D profiles obtained from various techniques.

• Proceedings of the KIEE Conference
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• 1999.11c
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• pp.482-484
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• 1999

In this paper, we propose a voting method for capacitance measurement. Nowadays the measurement system is changing from analog system to digital system. However, capacitance measurement system has a data error because of the noise. The data of general digital measurement system include an internal and external measurement noises that highly affect to the results. Therefore, this paper proposes data compensation method using voting method. Finally, simulation results are used to demonstrate the efficiency of the proposed method.

• Korean Journal of Materials Research
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• v.29 no.7
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• pp.408-411
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• 2019

ZTO/n-Si thin film is produced to investigate tunneling phenomena by interface characteristics by the depletion layer. For diversity of the depletion layer, the thin film of ZTO is heat treated after deposition, and the gpolarization is found to change depending on the heat treatment temperature and capacitance. The higher the heat treatment temperature is, the higher the capacitance is, because more charges are formed, the highest at $150^{\circ}C$. The capacitance decreases at $200^{\circ}C$ ZTO heat treated at $150^{\circ}C$ shows tunneling phenomena, with low non-resistance and reduced charge concentration. When the carrier concentration is low and the resistance is low, the depletion layer has an increased potential barrier, which results in a tunneling phenomenon, which results in an increase in current. However, the ZTO thin film with high charge or high resistance shows a Schottky junction feature. The reason for the great capacitance increase is the increased current due to tunneling in the depletion layer.

• Composites Research
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• v.26 no.6
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• pp.337-342
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• 2013

The good dispersion of nano-materials in epoxy matrix was important parameter for the reinforcement effect, and the evaluation of dispersion degree was to prove it. This work was studied to predict the dispersion condition of nano-SiC powders in SiC/epoxy composites using capacitance measurement. Capacitance was defined to be the electric capacity in proportional to electron charge of the measuring section. In case of nano-SiC powders, the electron charge of SiC/epoxy composites was higher than that of neat epoxy resin. Capacitance was evaluated for each section of SiC/epoxy composites. The prediction of dispersion condition was verified by using capacitance measurement. Dispersion condition of nano-SiC powders in epoxy matrix was evaluated with two different dispersion methods, i.e., sonication and stirring methods. The dispersion degree was also verified with the tensile strength correlating to capacitance.

• Tribology and Lubricants
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• v.11 no.5
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• pp.71-77
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• 1995

The capacitance technique was used to measure the minimum oil film thickness in engine bearing and the central oil film thickness between cam and tappet. This method is based on the measurement of total capacitance of oil film. For the measurement of the oil film thickness between cam and tappet, two surfaces were assumed to be flat and parallel within the Hertzian region and all the measured capacitance originated from this region. Shear rates from the measured minimum oil film thickness are over 10$^{6}$ sec$^{-1}$ in the greater part in both two cases. The minimum oil film thickness in engine bearing is larger than the surface roughness. Between cam and tappet it is mostly smaller than the surface roughness. In spite of the awkward restriction of the reliability of measured oil film thickness, it was known that the capacitance technique makes it possible to measure the oil film thickness in elastohydrodynamic and mixed lubrication regimes as well as in hydrodynamic regime. Therefore, it is also possible to classify the lubrication regimes based on the oil film thickness.

• Journal of Sensor Science and Technology
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• v.17 no.3
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• pp.195-202
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• 2008

A biosensor based on the measurement of capacitance changes has been designed and fabricated for simple and realtime detection of bacteria. Compared to an impedance measurement technique, the capacitance measurement can make additional measurement circuits simpler, which improves a compatability for integration between the sensor and circuit. The fabricated sensor was characterized by detecting Escherichia coli(E. coli). The capacitance changes measured by the sensor were proportional to E. coli cell density, and the proposed sensor could detect $1{\times}10^6$ cfu/ml E. coli at least. The real-time detection was verified by measuring the capacitance every 20 minutes. After 7 hours of E. coli growth experiment, the capacitance of the sensor in the micro volume well with $4.5{\times}10^5$ cfu/ml of initial E. coli density increased by 20 pF, and that in another wells with $1.5{\times}10^6$ cfu/ml and $8.5{\times}10^7$ cfu/ml initial E. coli density increased by 56 pF and 71 pF, respectively. The proposed sensor has a possibility of the real-time detection for bacterial growth, and can detect E. coli cells with $1.8{\times}10^5$ cfu in nutrient broth in 5 hours.

• Progress in Medical Physics
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• v.3 no.2
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• pp.43-57
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• 1992

Phase detector techique provides a unique probe to membrane recycling phenomenon by enabling dynamic monitoring of cell membrane capacitance. However, it has inherent errors due to constant changes in measurement environments. The present study analyzed several error sources to develope application criteria of this technique. and the following was found based on a theoretical analysis. The initial phase angle has to be appropriately selected to minimize the error due to perturbation of access and membrane conductances. Excitation frequency is also important to determine the initial phase angle. However. deviation of the phase angle from a predetermined initial value during the measurement period does not affect capacitance estimation to a significant degree. Despite an appropriate initial phase selection an error in scaling factor is expected for a large increase in capacitance during exocytosis. which may be overcome by iteratively correcting the scaling factor over the measurement period. These results will provide a useful guideline in practical application of this technique.

• Journal of the Korean Geotechnical Society
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• v.22 no.7
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• pp.45-54
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• 2006

Resistivity cone penetrometer test (RCPT) can be employed at a relatively low cost for in-situ delineation of subsurface contamination. While the resistivity measurement has a potential to investigate the subsurface contamination, resistivity measurements alone will lead to some degree of ambiguity in the results. In this study, capacitance measurement was incorporated into the RCPT to overcome the ambiguity inherent in electrical resistivity measurements. This study is focused on verifying the applicability of resistivity and capacitance measurements of CPT module to provide information on subsurface contaminated by heavy metal and petroleum hydrocarbon. Laboratory model tests were performed to evaluate the sensitivity of the measured resistivity and relative capacitance on the water content and different types of contaminants. Test results show that simultaneous measurement of electrical resistivity and capacitance can give more reliable information on subsurface contamination. Electrical measurements of the CPT module showed high applicability to be used in detecting saturated soils contaminated by heavy metal and diesel plume floating above the groundwater table.

• Journal of the Korean Applied Science and Technology
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• v.24 no.4
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• pp.377-382
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• 2007

We designed capacitance sensor in order to examine characteristics of W/O type emulsified fuel, so it concluded the following conclusions. The capacitance value of emulsified fuel, using with capacitance sensor, increases as water content increases due to the coalescence. When surfactant increases, the capacitance value decreases, the condition of W/O type emulsified fuel was maintained stably. There was revealed the capacitance value difference of W/O type emulsified fuel in in according to water content. We checked the phase separation of emulsified fuel with the capacitance value difference. The surfactant(HLB=5.4) had better stable condition than surfactant(HLB=4.3). Also, we confirmed that two mixture surfactants were better than one surfactant.